LP#1013786 TPAC add reminder to modify update_pasword_msg.tt2 to global.password_regex

LP#1013786 TPAC add reminder to modify update_pasword_msg.tt2 to global.password_regex

Currently, libraries can configure their own password strength regular expressions
via the Library Settings Editor.  This, however, did not provide a reminder
that the message shown to the patron when resetting their password needed to
meet those requirements.

This patch provides a hint in the description of the YAOUS global.password_regex
to remind that update_password_msg.tt2 should be updated with a user-friendly
text string explaining the password requirements if they are changed from the default.

Signed-off-by: Michael Peters <mpeters@emeralddata.net>