chan_sip: Reload peer without its old capabilities.

On reload, previously allowed codecs were not removed. Therefore, it was not
possible to remove codecs while Asterisk was running. Furthermore, newly added
codecs got appended behind the previous codecs. Therefore, it was not possible
to add a codec with a priority of #1. This change removes the old capabilities
before the current ones are added.

ASTERISK-25182 #close
Reported by: Alexander Traud
patches:
 asterisk_13_allow_codec_reload.patch uploaded by Alexander Traud (License 6520)

Change-Id: I62a06bcf15e08e8c54a35612195f97179ebe5802

channels/chan_sip.c

@@ -30424,8 +30424,11 @@ static struct sip_peer *build_peer(const char *name, struct ast_variable *v, str
 		if (!ast_sockaddr_isnull(&peer->addr)) {
 			ao2_t_unlink(peers_by_ip, peer, "ao2_unlink peer from peers_by_ip table");
 		}
-		if (!(peer->the_mark))
+		if (!(peer->the_mark)) {
 			firstpass = 0;
+		} else {
+			ast_format_cap_remove_by_type(peer->caps, AST_MEDIA_TYPE_UNKNOWN);
+		}
 	} else {
 		if (!(peer = ao2_t_alloc(sizeof(*peer), sip_destroy_peer_fn, "allocate a peer struct"))) {
 			return NULL;