MINOR: hlua/event_hdl: rely on proxy_uuid instead of proxy_name for lookups

Since "MINOR: server/event_hdl: add proxy_uuid to event_hdl_cb_data_server"
we may now use proxy_uuid variable to perform proxy lookups when
handling a server event.

It is more reliable since proxy_uuid isn't subject to any size limitation
diff --git a/src/hlua.c b/src/hlua.c
index 91c3abb..e6856c8 100644
--- a/src/hlua.c
+++ b/src/hlua.c
@@ -9063,7 +9063,7 @@
 		/* attempt to provide reference server object
 		 * (if it wasn't removed yet, SERVER_DEL will never succeed here)
 		 */
-		px = proxy_find_by_name(e_server->safe.proxy_name, PR_CAP_BE, 0);
+		px = proxy_find_by_id(e_server->safe.proxy_uuid, PR_CAP_BE, 0);
 		BUG_ON(!px);
 		server = findserver_unique_id(px, e_server->safe.puid, e_server->safe.rid);
 		if (server) {