real update .files db in background

src/system_daemon.vala

@@ -141,8 +141,8 @@ namespace Pamac {
 					(alpm_action) => {
 						alpm_action.run ();
 					},
-					// only one thread created so alpm action will run one after one 
-					1,
+					// two threads at a time
+					2,
 					// no exclusive thread
 					false
 				);

src/transaction.vala

@@ -456,6 +456,9 @@ namespace Pamac {
 		}
 
 		public void start_refresh (bool force) {
+			check_authorization.begin ((obj, res) => {
+				bool authorized = check_authorization.end (res);
+				if (authorized) {
 					string action = dgettext (null, "Synchronizing package databases") + "...";
 					reset_progress_box (action);
 					connecting_system_daemon ();
@@ -470,6 +473,8 @@ namespace Pamac {
 						finish_transaction ();
 					}
 				}
+			});
+		}
 
 		public void refresh_handle () {
 			try {