Make a debug message regarding subscription changes more accurate.

I was getting confused during some testing why Asterisk was saying that
a subscription was being added when it was clearly being removed. This
fixes that confusion.
........

Merged revisions 360625 from http://svn.asterisk.org/svn/asterisk/branches/1.8
........

Merged revisions 360672 from http://svn.asterisk.org/svn/asterisk/branches/10


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@360673 65c4cc65-6c06-0410-ace0-fbb531ad65f3

channels/chan_sip.c

@@ -25886,12 +25886,15 @@ static int handle_request_subscribe(struct sip_pvt *p, struct sip_request *req,
 		}
 
 		if (sipdebug) {
+			const char *action = p->expiry > 0 ? "Adding" : "Removing";
 			if (p->subscribed == MWI_NOTIFICATION && p->relatedpeer) {
-				ast_debug(2, "Adding subscription for mailbox notification - peer %s\n", p->relatedpeer->name);
+				ast_debug(2, "%s subscription for mailbox notification - peer %s\n",
+						action, p->relatedpeer->name);
 			} else if (p->subscribed == CALL_COMPLETION) {
-				ast_debug(2, "Adding CC subscription for peer %s\n", p->username);
+				ast_debug(2, "%s CC subscription for peer %s\n", action, p->username);
 			} else {
-				ast_debug(2, "Adding subscription for extension %s context %s for peer %s\n", p->exten, p->context, p->username);
+				ast_debug(2, "%s subscription for extension %s context %s for peer %s\n",
+						action, p->exten, p->context, p->username);
 			}
 		}
 		if (p->autokillid > -1 && sip_cancel_destroy(p))	/* Remove subscription expiry for renewals */