Merge pull request #1050 from zhouer/close_request

Handle close request event for main window, fixes #1040

main/ui/src/main/java/org/cryptomator/ui/mainwindow/MainWindowTitleController.java

@@ -57,6 +57,10 @@ public class MainWindowTitleController implements FxController {
 			window.setX(event.getScreenX() - xOffset);
 			window.setY(event.getScreenY() - yOffset);
 		});
+		window.setOnCloseRequest(event -> {
+			close();
+			event.consume();
+		});
 	}
 
 	@FXML