Fix crash for sorcery misconfigs

res_pjsip_outbound_publish was missing the CHECK_PJSIP_MODULE_LOADED()
call in load_module, and would crash with a segfault if res_pjsip
declined to load.

Review: https://reviewboard.asterisk.org/r/4258/
........

Merged revisions 429457 from http://svn.asterisk.org/svn/asterisk/branches/13


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@429458 65c4cc65-6c06-0410-ace0-fbb531ad65f3