Check expiration every hour regardless of the duration.

src/loop.c

@@ -84,7 +84,7 @@ int mosquitto_main_loop(struct mosquitto_db *db, int *listensock, int listensock
 #endif
 
 	if(db->config->persistent_client_expiration > 0){
-		expiration_check_time = time(NULL) + db->config->persistent_client_expiration;
+		expiration_check_time = time(NULL) + 3600;
 	}
 
 	while(run){
@@ -250,7 +250,7 @@ int mosquitto_main_loop(struct mosquitto_db *db, int *listensock, int listensock
 					}
 				}
 			}
-			expiration_check_time = time(NULL) + db->config->persistent_client_expiration;
+			expiration_check_time = time(NULL) + 3600;
 		}
 
 		mqtt3_db_message_timeout_check(db, db->config->retry_interval);