Description of problem:

Source repository field in customer migration targets doesn't have format validation

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

6.1.2

How reproducible:

100%

Steps to Reproduce:

1. Go to Administration => Custom migration targets
2. Create a new one
3. In source repository field enter just several spaces

Actual results:

Create button will become active, no format validation

Expected results:

Helper message should appear that URL format is incorrect

Additional info:

The issue is relevant for custom rules on analysis wizard as well, the "Next" button is enabled