res_pjsip: Fix for Doxygen.

include/asterisk/res_pjsip.h

include/asterisk/res_pjsip_cli.h

include/asterisk/res_pjsip_presence_xml.h

include/asterisk/res_pjsip_pubsub.h

include/asterisk/res_pjsip_session.h

include/asterisk/res_pjsip_session_caps.h

res/res_pjsip/config_global.c

res/res_pjsip/config_transport.c

res/res_pjsip/include/res_pjsip_private.h

res/res_pjsip/pjsip_distributor.c

res/res_pjsip/pjsip_transport_events.c

res/res_pjsip_authenticator_digest.c

res/res_pjsip_caller_id.c

res/res_pjsip_history.c

res/res_pjsip_messaging.c

res/res_pjsip_outbound_authenticator_digest.c

res/res_pjsip_outbound_registration.c

res/res_pjsip_path.c

res/res_pjsip_publish_asterisk.c

res/res_pjsip_pubsub.c