Update "no listeners" message for service_checkin.

Author: michaelrsweet

scheduler/main.c

@@ -2043,9 +2043,7 @@ service_checkin(void)
     * No listeners!
     */
 
-    cupsdLogMessage(CUPSD_LOG_EMERG,
-                    "No valid Listen or Port lines were found in the "
-		    "configuration file.");
+    cupsdLogMessage(CUPSD_LOG_EMERG, "service_checkin: No listener sockets present.");
 
    /*
     * Commit suicide...