sipsess/connect: set sess->established immediately on 200 receival

Otherwise, if something in invite_resp_handler fails and
sipsess_terminate is called, no BYE will be sent.

src/sipsess/connect.c

@@ -148,22 +148,22 @@ static void invite_resp_handler(int err, const struct sip_msg *msg, void *arg)
 	}
 	else if (msg->scode < 300) {
 
+		sess->established = true;
+
 		sess->hdrs = mem_deref(sess->hdrs);
 
 		err = sip_dialog_established(sess->dlg) ?
 				sip_dialog_update(sess->dlg, msg) :
 				sip_dialog_create(sess->dlg, msg);
-		if (err)
-			goto out;
 
 		if (sdp) {
 			if (sess->neg_state == SDP_NEG_LOCAL_OFFER) {
 				sess->neg_state = SDP_NEG_DONE;
-				err = sess->answerh(msg, sess->arg);
+				err |= sess->answerh(msg, sess->arg);
 			}
 			else if (sess->neg_state == SDP_NEG_NONE) {
 				sess->neg_state = SDP_NEG_REMOTE_OFFER;
-				err = sess->offerh(&desc, msg, sess->arg);
+				err |= sess->offerh(&desc, msg, sess->arg);
 			}
 		}
 
@@ -179,7 +179,6 @@ static void invite_resp_handler(int err, const struct sip_msg *msg, void *arg)
 		    && mbuf_get_left(desc))
 			sess->neg_state = SDP_NEG_DONE;
 
-		sess->established = true;
 		mem_deref(desc);
 
 		if (err || sess->terminated)