Issue #7924 - cmaj - Turn off silence suppression if no channel owner

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@42827 65c4cc65-6c06-0410-ace0-fbb531ad65f3

channels/chan_sip.c

@@ -5996,7 +5996,7 @@ static int add_sdp(struct sip_request *resp, struct sip_pvt *p)
 	if (option_debug > 2)
 		ast_log(LOG_DEBUG, "-- Done with adding codecs to SDP\n");
-	if(!ast_internal_timing_enabled(p->owner))
+	if(!p->owner || !ast_internal_timing_enabled(p->owner))
 		ast_build_string(&a_audio_next, &a_audio_left, "a=silenceSupp:off - - - -\r\n");
 	if ((m_audio_left < 2) || (m_video_left < 2) || (a_audio_left == 0) || (a_video_left == 0))