Can't upgrade to remote build, az crashed

### **This is autogenerated. Please review and update as needed.**

## Describe the bug

**Command Name**
`az functionapp update`

**Errors:**
```
'NoneType' object has no attribute 'kind'
Traceback (most recent call last):
python3/dist-packages/knack/cli.py, ln 206, in invoke
cmd_result = self.invocation.execute(args)
cli/core/commands/__init__.py, ln 608, in execute
raise ex
cli/core/commands/__init__.py, ln 666, in _run_jobs_serially
results.append(self._run_job(expanded_arg, cmd_copy))
cli/core/commands/__init__.py, ln 657, in _run_job
cmd_copy.exception_handler(ex)
...
cli/core/commands/__init__.py, ln 419, in cached_put
return _put_operation()
cli/core/commands/__init__.py, ln 414, in _put_operation
result = operation(parameters=parameters, **kwargs)
cli/command_modules/appservice/custom.py, ln 574, in set_functionapp
if 'function' not in instance.kind:
AttributeError: 'NoneType' object has no attribute 'kind'
```

## To Reproduce:
Steps to reproduce the behavior. Note that argument values have been redacted, as they may contain sensitive information.

- _Put any pre-requisite steps here..._
- `az functionapp update -g {} -n {}`

## Expected Behavior

## Environment Summary
```
Linux-5.4.0-74-generic-x86_64-with-glibc2.29
Python 3.8.10
Shell: bash

azure-cli 2.0.81

Extensions:
azure-devops 0.17.0

```
## Additional Context