fix style and indentation

src/preferences_dialog.vala

@@ -342,7 +342,7 @@ namespace Pamac {
 		void on_write_mirrors_config_finished (string choosen_country, string choosen_generation_method) {
 			int index = 0;
 			string choosen_country_ = dgettext (null, "Worldwide");
-			if ( choosen_country != "ALL") {
+			if (choosen_country != "ALL") {
 				choosen_country_ = choosen_country;
 			}
 			mirrors_country_comboboxtext.model.foreach ((model, path, iter) => {