Bug 14820: Add missing prefs SMSSendUsername and SMSSendPassword

Bug 14820: Add missing prefs SMSSendUsername and SMSSendPassword

These 2 system preferences are missing from the sysprefs.sql file.

Test plan:
Execute the updatedatabase script and confirm that the 2 prefs are now
in the systempreferences table.
Search for "sms" in the system preferences search box, you should see
the 3 prefs.

Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Tomas Cohen Arazi <tomascohen@unc.edu.ar>
(cherry picked from commit 39dc8b5a9da902f9f90850421dc2815e448222e5)
Signed-off-by: Chris Cormack <chrisc@catalyst.net.nz>