Description of problem:

Cannot detach associated credentials when editing a custom target card

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

mta-operator-bundle-container-7.0.0-41

How reproducible:

100%

Steps to Reproduce:

1. As administrator, create a source credential
2. Go to Custom migration targets -> Click "Create new"
3. Select "Retrieve from a repository" -> fill the required fields and attach the created credentials -> Click "Create"
4. Edit the custom target card -> try to detach the associated credentials

Actual results:

Cannot detach associated credentials

Expected results:

Clicking on the selected credential in the droplist will remove it