Description of problem:
If git credentials were changed and "Refresh with a new branch or tag" was performed there is no flash message that warns a user about it.
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1. Import automate datastore from a private git repo.
2. Change credentials of that repo.
3. Navigate to Automation/Automate/Explorer.
4. Click "Refresh with a new branch or tag"
Nothing happened in the UI, in the logs you can find such line: [----] E, [2018-04-23T08:13:41.121296 #11900:8e7114] ERROR -- : MIQ(MiqQueue#deliver) Message id: , Error: [Invalid credentials for URL https://some_url/somne_manageiq_datastore.git]
There should be a flash message about wrong credentials.
This BZ follows up https://bugzilla.redhat.com/show_bug.cgi?id=1568602