Description of problem:
If Bugzilla rejects a bug submission and tells the user to go back and try again, the bug description (which the user may have spent significant time crafting) gets replaced by the default template text.

Version-Release number of selected component (if applicable):
5.0.3 (beta.bugzilla.redhat.com)

How reproducible:
Always

Steps to Reproduce:
1. Go to New->Community-Bugzilla
2. Select a component and enter a bug Summary and Description
3. Request the needinfo flag from an account that is disabled. 
4. Click submit
5. Click the browser's Back button

Actual results:
After step 4, Bugzilla correctly say "You can't ask <foo@example.com> because that account is disabled.\nPlease press Back and try again."
After step 5, the bug Description entered in step 2 has been replaced by the default template text.

Expected results:
After step 5, the original bug description is intact.

Additional info:
- I consider this bug to be high priority due to the potential for users to lose a significant amount of work when their text is thrown away.
- Marked as a regression -- it doesn't happen in Bugzilla 4.x because that version doesn't object to requesting flags from a disabled account.