Bug 30207: Librarians with only "place_holds" permission can no longer update hold...

Bug 30207: Librarians with only "place_holds" permission can no longer update hold pickup locations

Bug 29540 increased the flags required to for modreserve.pl, but in doing so created a situation where a library can select a different pickup location for a hold, but upon clicking the "Update hold(s)" button, will be logged out due to having insufficient permissions for modreserve.pl.

Test Plan:
1) Create a librarian with "place_holds" permissions, but not "modify_holds_priority".
2) Place a hold for a patron
3) Attempt to change the pickup location from request.pl
4) Note you get logged out with a permissions error
5) Apply this patch
6) Restart all the things!
7) Attempt to change the pickup location from request.pl
8) This time it should succeed!

Signed-off-by: Christopher Brannon <cbrannon@cdalibrary.org>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>