Turn if/else branch for valid compare error message
Created by: Razer6
What does this MR do?
This PR switches the error messages, if compare logic can't provide a comparison result.
Why was this MR needed?
If we're comparing the same revision, UI says You'll need to use different branch names to get a valid comparison.
. If it can't compare for some reason (e.g. branch doesn't exist), it says branch1 and master are the same
.
What are the relevant issue numbers?
This is related to #7446