Remove the "Event: registration" header from Asterisk-generated

SIP REGISTER requests. rjain points out that RFC 3265 specifies
that the Event: header is not a valid header for REGISTER requests
and that the "registration" value is not defined at IANA.

(closes issue #12279)
Reported by: rjain
Patches:
      chan_sip.c.diff uploaded by rjain (license 226)



git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@110621 65c4cc65-6c06-0410-ace0-fbb531ad65f3

channels/chan_sip.c

@@ -9381,7 +9381,6 @@ static int transmit_register(struct sip_registry *r, int sipmethod, const char *
 	snprintf(tmp, sizeof(tmp), "%d", r->expiry);
 	add_header(&req, "Expires", tmp);
 	add_header(&req, "Contact", p->our_contact);
-	add_header(&req, "Event", "registration");
 	add_header_contentLength(&req, 0);
 
 	initialize_initreq(p, &req);