[ticket/12804] Hide Jabber from UCP & member search when disabled

PHPBB3-12804
[ticket/12804] Hide jabber for subSilver2 as well

PHPBB3-12804
[ticket/12804] Dont use ternary form

PHPBB3-12804
[ticket/12804] Disable jabber from memberlist sort options

PHPBB3-12804
Merge remote-tracking branch 'paybas/ticket/12804' into develop-ascraeus