fix project quota showing error and success message

right now if you try to change a quota value to something less than what is currently
used, it will give you both error and success message
fix test cases to check for 2 errors messages

Change-Id: I25550346e553b1469b321cd46b2eeff612f11869
Closes-Bug: #1278353
Merge "fix project quota showing error and success message"