linux-arm debugging of published exe hangs

## Environment data
On the target RPi:
Microsoft .NET Core Shared Framework Host
Version : 2.1.0-preview1-26216-03
Build : f2c3216183d20416568a4bbf5bb7d153e826f153

VSCode IDE running on Windows 10.

VS Code version: 1.21.1
C# Extension version: 1.14.0

## Steps to reproduce
Follow steps in https://github.com/OmniSharp/omnisharp-vscode/wiki/Remote-Debugging-On-Linux-Arm

## Expected behavior
Able to debug a "published" executable

## Actual behaviour
Debugger starts then hangs

I have followed the instructions and can debug a simple console application running on my RPi. Impressive! When I try to follow the instructions for Self-Contained Deployment the debugger starts (giving the "You may only use the Microsoft .NET Core Debugger (vsdbg) with..." notification then hangs until I stop the debugger.

I can run the executable manually OK.

My launch.json contains these two options (the first works for the Framework Dependent version):
```
{
"name": "Remote",
"type": "coreclr",
"request": "launch",
"program": "/opt/dotnet/dotnet",
"args": ["./MyConsoleApp.dll"],
"cwd": "/home/pi/dev/repos/Raspberry Pi Test/src/temp/MyConsoleApp/bin/Debug/netcoreapp2.1",
"stopAtEntry": false,
"console": "internalConsole",
"logging": {
"engineLogging": true
},
"pipeTransport": {
"pipeCwd": "${workspaceRoot}",
"pipeProgram": "c:\\Program Files\\PuTTY\\plink.exe",
"pipeArgs": [
"-i",
"C:\\Users\\piers\\ssh-key.ppk",
"pi@piers01"
],
"debuggerPath": "sudo /opt/vsdbg/vsdbg"
}
},
{
"name": "RemotePublished",
"type": "coreclr",
"request": "launch",
"program": "MyConsoleApp",
"args": [],
"cwd": "/home/pi/dev/repos/Raspberry Pi Test/src/temp/MyConsoleApp/bin/Debug/netcoreapp2.1/linux-arm/publish",
"stopAtEntry": false,
"console": "internalConsole",
"logging": {
"engineLogging": true
},
"pipeTransport": {
"pipeCwd": "${workspaceRoot}",
"pipeProgram": "c:\\Program Files\\PuTTY\\plink.exe",
"pipeArgs": [
"-i",
"C:\\Users\\piers\\ssh-key.ppk",
"pi@piers01"
],
"debuggerPath": "sudo /opt/vsdbg/vsdbg"
}
```