app_lua: updated the utils/app_lua_ctl

(cherry picked from commit ac8cc0a3735325ec79a4a634eea6bcdcea4affe7)
(cherry picked from commit d56ec1c20796e9a32790d880c0ab9a4ee579216e)

src/modules/app_lua/utils/app_lua_ctl

@@ -142,6 +142,9 @@ lua_CFunction sr_kemi_lua_export_associate(sr_kemi_t *ket)
 			_sr_kemi_lua_export_list[i].ket = ket;
 			return _sr_kemi_lua_export_list[i].pfunc;
 		}
+		if(_sr_kemi_lua_export_list[i].ket==ket) {
+			return _sr_kemi_lua_export_list[i].pfunc;
+		}
 	}
 	LM_ERR("no more indexing slots\n");
 	return NULL;