Bug 7697: Remove unused textmessaging parameter from OPAC main/user

Bug 7697: Remove unused textmessaging parameter from OPAC main/user

Removes the textmessaging parameter from opac/opac-main.pl and
opac/opac-user.pl, since it's not utilized anywhere in the templates, and is
sourced from a field that no longer exists in the borrower
table (textmessaging).

This also removes a dependency on C4/Members.pm from opac-main.pl

To Test:  Login to the OPAC, and view both opac-user.pl and opac-main.pl. Both
pages should still render properly.

Signed-off-by: Jared Camins-Esakov <jcamins@cpbibliography.com>
Signed-off-by: Paul Poulain <paul.poulain@biblibre.com>