Max credit adjustment shows even if amount not adjusted

Org has 725 credits left, upon entering 725 I get the warning that the amount was adjust, but I entered 725 and it was not actually adjusted. This leads the user to being confused.

Start by reproducing the credit adjustment form with an organization showing 725 credits, then enter 725 and inspect when the adjustment warning appears. Trace the form entry point and validation logic responsible for the warning. Done means the warning is not shown when the entered amount is unchanged, while it still appears when an actual adjustment occurs.

Written by the indexing model from the issue text.