Remove files left behind on removal of h323, jingle and jabber.

This change removes h323.conf.sample, jingle.h, jabber.h left behind by r3698.

Review: https://reviewboard.asterisk.org/r/3755/


git-svn-id: http://svn.asterisk.org/svn/asterisk/trunk@418448 f38db490-d61c-443f-a65b-d21fe96a405b