Description of problem:
If the user enters a character like "a" into the search field, then deletes it, an exception occurs.

Version-Release number of selected component (if applicable):
3.7-snapshot

How reproducible:
Easy always

Steps to Reproduce:
1. With a large (eg. production size) database to test on, enter "a" into the project search
2. Delete the character

Actual results:
javax.servlet.ServletException: UT000047: The number of parameters exceeded the maximum of 1000

Expected results:
No response

Additional info:
Happens when the list of users returned by the "a" search is very large.