Comment 6 for bug 1776917

Hello, here's a patch that takes care of the issue:

http://git.evergreen-ils.org/?p=working/Evergreen.git;a=shortlog;h=refs/heads/user/cesardv/lp1776917-patron_bills_grid_require_billID

Kudos to Christopher for pointing us towards a temp. workaround, and hinting us onto the source of the issue.