Empty staticwebapp.config.json throws unhandled exception; should print something useful

**Describe the bug**

Azure Pipelines is encountering a "Unknown Exception". More in

**To Reproduce**
Steps to reproduce the behavior:
1. Go to Azure Pipelines
2. Click on latest build
3. Scroll down to '....'
4. See error

>
> Linking with emcc. This may take a while ...
> "/opt/dotnet/6.0.100/packs/Microsoft.NET.Runtime.Emscripten.2.0.23.Sdk.linux-x64/6.0.0/tools/bin/wasm-ld" -o /working_dir/src/obj/Release/net6/wasm/for-publish/dotnet.wasm /working_dir/src/obj/Release/net6/wasm/for-publish/pinvoke.o /working_dir/src/obj/Release/net6/wasm/for-publish/driver.o /working_dir/src/obj/Release/net6/wasm/for-publish/corebindings.o /opt/dotnet/6.0.100/packs/Microsoft.NETCore.App.Runtime.Mono.browser-wasm/6.0.1/runtimes/browser-wasm/native/libicui18n.a /opt/dotnet/6.0.100/packs/Microsoft.NETCore.App.Runtime.Mono.browser-wasm/6.0.1/runtimes/browser-wasm/native/libicuuc.a /opt/dotnet/6.0.100/packs/Microsoft.NETCore.App.Runtime.Mono.browser-wasm/6.0.1/runtimes/browser-wasm/native/libmono-component-debugger-stub-static.a /opt/dotnet/6.0.100/packs/Microsoft.NETCore.App.Runtime.Mono.browser-wasm/6.0.1/runtimes/browser-wasm/native/libmono-component-diagnostics_tracing-stub-static.a /opt/dotnet/6.0.100/packs/Microsoft.NETCore.App.Runtime.Mono.browser-wasm/6.0.1/runtimes/browser-wasm/native/libmono-component-hot_reload-stub-static.a /opt/dotnet/6.0.100/packs/Microsoft.NETCore.App.Runtime.Mono.browser-wasm/6.0.1/runtimes/browser-wasm/native/libmono-ee-interp.a /opt/dotnet/6.0.100/packs/Microsoft.NETCore.App.Runtime.Mono.browser-wasm/6.0.1/runtimes/browser-wasm/native/libmono-icall-table.a /opt/dotnet/6.0.100/packs/Microsoft.NETCore.App.Runtime.Mono.browser-wasm/6.0.1/runtimes/browser-wasm/native/libmono-ilgen.a /opt/dotnet/6.0.100/packs/Microsoft.NETCore.App.Runtime.Mono.browser-wasm/6.0.1/runtimes/browser-wasm/native/libmono-profiler-aot.a /opt/dotnet/6.0.100/packs/Microsoft.NETCore.App.Runtime.Mono.browser-wasm/6.0.1/runtimes/browser-wasm/native/libmonosgen-2.0.a /opt/dotnet/6.0.100/packs/Microsoft.NETCore.App.Runtime.Mono.browser-wasm/6.0.1/runtimes/browser-wasm/native/libSystem.IO.Compression.Native.a /opt/dotnet/6.0.100/packs/Microsoft.NETCore.App.Runtime.Mono.browser-wasm/6.0.1/runtimes/browser-wasm/native/libSystem.Native.a -L/opt/dotnet/6.0.100/packs/Microsoft.NET.Runtime.Emscripten.2.0.23.Sdk.linux-x64/6.0.0/tools/emscripten/cache/sysroot/lib/wasm32-emscripten /opt/dotnet/6.0.100/packs/Microsoft.NET.Runtime.Emscripten.2.0.23.Sdk.linux-x64/6.0.0/tools/emscripten/cache/sysroot/lib/wasm32-emscripten/libgl.a /opt/dotnet/6.0.100/packs/Microsoft.NET.Runtime.Emscripten.2.0.23.Sdk.linux-x64/6.0.0/tools/emscripten/cache/sysroot/lib/wasm32-emscripten/libal.a /opt/dotnet/6.0.100/packs/Microsoft.NET.Runtime.Emscripten.2.0.23.Sdk.linux-x64/6.0.0/tools/emscripten/cache/sysroot/lib/wasm32-emscripten/libhtml5.a /opt/dotnet/6.0.100/packs/Microsoft.NET.Runtime.Emscripten.2.0.23.Sdk.linux-x64/6.0.0/tools/emscripten/cache/sysroot/lib/wasm32-emscripten/libc.a /opt/dotnet/6.0.100/packs/Microsoft.NET.Runtime.Emscripten.2.0.23.Sdk.linux-x64/6.0.0/tools/emscripten/cache/sysroot/lib/wasm32-emscripten/libcompiler_rt.a /opt/dotnet/6.0.100/packs/Microsoft.NET.Runtime.Emscripten.2.0.23.Sdk.linux-x64/6.0.0/tools/emscripten/cache/sysroot/lib/wasm32-emscripten/libc++.a /opt/dotnet/6.0.100/packs/Microsoft.NET.Runtime.Emscripten.2.0.23.Sdk.linux-x64/6.0.0/tools/emscripten/cache/sysroot/lib/wasm32-emscripten/libc++abi.a /opt/dotnet/6.0.100/packs/Microsoft.NET.Runtime.Emscripten.2.0.23.Sdk.linux-x64/6.0.0/tools/emscripten/cache/sysroot/lib/wasm32-emscripten/libdlmalloc.a /opt/dotnet/6.0.100/packs/Microsoft.NET.Runtime.Emscripten.2.0.23.Sdk.linux-x64/6.0.0/tools/emscripten/cache/sysroot/lib/wasm32-emscripten/libc_rt_wasm.a /opt/dotnet/6.0.100/packs/Microsoft.NET.Runtime.Emscripten.2.0.23.Sdk.linux-x64/6.0.0/tools/emscripten/cache/sysroot/lib/wasm32-emscripten/libsockets.a -mllvm -combiner-global-alias-analysis=false -mllvm -enable-emscripten-cxx-exceptions -mllvm -enable-emscripten-sjlj -mllvm -disable-lsr --allow-undefined --export putchar --export stackSave --export stackRestore --export stackAlloc --export __wasm_call_ctors --export __errno_location --export malloc --export free --export __cxa_is_pointer_type --export __cxa_can_catch --export setThrew --export _get_tzname --export _get_daylight --export _get_timezone --export ntohs --export htons --export htonl --export memset --export memalign --export emscripten_main_thread_process_queued_calls --export-if-defined=__start_em_asm --export-if-defined=__stop_em_asm --export-table -z stack-size=5242880 --initial-memory=536870912 --no-entry --max-memory=2147483648 --global-base=1024
"/opt/dotnet/6.0.100/packs/Microsoft.NET.Runtime.Emscripten.2.0.23.Sdk.linux-x64/6.0.0/tools/bin/wasm-emscripten-finalize" --minimize-wasm-changes -g --dyncalls-i64 /working_dir/src/obj/Release/net6/wasm/for-publish/dotnet.wasm -o /working_dir/src/obj/Release/net6/wasm/for-publish/dotnet.wasm --detect-features
"/opt/dotnet/6.0.100/packs/Microsoft.NET.Runtime.Emscripten.2.0.23.Node.linux-x64/6.0.0/tools/bin/node" /opt/dotnet/6.0.100/packs/Microsoft.NET.Runtime.Emscripten.2.0.23.Sdk.linux-x64/6.0.0/tools/emscripten/src/compiler.js /tmp/tmp3cxmozdd.txt
"/opt/dotnet/6.0.100/packs/Microsoft.NET.Runtime.Emscripten.2.0.23.Sdk.linux-x64/6.0.0/tools/bin/wasm-opt" --strip-dwarf --post-emscripten --no-exit-runtime -O2 --low-memory-unused --zero-filled-memory --strip-debug --strip-producers /working_dir/src/obj/Release/net6/wasm/for-publish/dotnet.wasm -o /working_dir/src/obj/Release/net6/wasm/for-publish/dotnet.wasm -g --mvp-features --enable-mutable-globals
"/opt/dotnet/6.0.100/packs/Microsoft.NET.Runtime.Emscripten.2.0.23.Node.linux-x64/6.0.0/tools/bin/node" /opt/dotnet/6.0.100/packs/Microsoft.NET.Runtime.Emscripten.2.0.23.Sdk.linux-x64/6.0.0/tools/emscripten/tools/acorn-optimizer.js /tmp/emscripten_temp_c92613kc/dotnet.js JSDCE minifyWhitespace
> Optimizing dotnet.wasm ...
> Compressing Blazor WebAssembly publish artifacts. This may take a while...
proto-apex-ui -> /ss-oryx/app/
> Preparing output...
>
> Removing existing manifest file
> Creating a manifest file...
> Manifest file created.
>
> Done in 150 sec(s).
>
>
> ---End of Oryx build logs---
> Finished building app with Oryx
> An unknown exception has occurred
>
> For further information, please visit the Azure Static Web Apps documentation at https://docs.microsoft.com/en-us/azure/static-web-apps/
> If you believe this behavior is unexpected, please raise a GitHub issue at https://github.com/azure/static-web-apps/issues/
> Exiting
> ##[error]Error: The process '/usr/bin/bash' failed with exit code 1
> Finishing: AzureStaticWebApp
>

staticwebapp.config.json

Currently a blank file (and quite possibly the issue)

Azure Pipeline Workflow YAML
```
# Starter pipeline
# Start with a minimal pipeline that you can customize to build and deploy your code.
# Add steps that build, run tests, deploy, and more:
# https://aka.ms/yaml

trigger:
- main

pool:
vmImage: 'ubuntu-latest'

steps:

- task: AzureStaticWebApp@0
inputs:
app_location: 'src'
output_location: '/ss-oryx/app/'
api_location: 'api'
api_build_command: 'none'
config_file_location: 'src'
azure_static_web_apps_api_token: 'REDACTED'

```
**Expected behavior**
The error should not report an "unknown exception" and instead report more info about the actual exception.