resolved: ignore our own LLMNR packets, the same way we ignore mDNS packets already

Let's minimize our traffic a bit. And for local names we bypass the
packet generation anyway.

src/resolve/resolved-llmnr.c

@@ -100,6 +100,9 @@ static int on_llmnr_packet(sd_event_source *s, int fd, uint32_t revents, void *u
         if (r <= 0)
                 return r;
 
+        if (manager_our_packet(m, p))
+                return 0;
+
         scope = manager_find_scope(m, p);
         if (!scope) {
                 log_debug("Got LLMNR UDP packet on unknown scope. Ignoring.");