Bug 16612 - Cannot set "Until date" for "Enrollment period" for Patron Categories

Bug 16612 - Cannot set "Until date" for "Enrollment period" for Patron Categories

Attempting to set an "Until date" date for "Enrollment period" will
result in the date being accepted but not saved.

Test Plan:
1) Attempt to set an enrollment period until date for a new patron category
2) Note the period is not saved
3) Apply this patch
4) Attempt to set the enrollment period date again
5) This time it should save!

Signed-off-by: Andrew Brenza <abrenza@audubonlibrary.org>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>