Description of problem:

The UI crashes when editing the channel URL of a AppSub app.

Version-Release number of selected component (if applicable):

How reproducible:

Steps to Reproduce:

1. Create an AppSub app but with a typo in the Git repo URL ie. https://github.com/fxiang1/app-sampless
2. Edit the app to correct the typo ie. remove the extra s from the URL https://github.com/fxiang1/app-samples
3. Save the change and the UI will crash

Actual results:

Expected results:

UI not to crash

Additional info: