Fix a bug where the Event and Content-Type headers were added twice to outgoing SIP NOTIFY messages.

(closes issue #15239)
Reported by: pj


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@198498 65c4cc65-6c06-0410-ace0-fbb531ad65f3

channels/chan_sip.c

@@ -10794,8 +10794,6 @@ static int transmit_state_notify(struct sip_pvt *p, int state, int full, int tim
 
 	reqprep(&req, p, SIP_NOTIFY, 0, 1);
 
-	add_header(&req, "Event", subscriptiontype->event);
-	add_header(&req, "Content-Type", subscriptiontype->mediatype);
 	switch(state) {
 	case AST_EXTENSION_DEACTIVATED:
 		if (timeout)