showing the window shouldn't be a decision made by the vault list controller.

when opening a .cryptomator file, the handler for open file requests is responsible for showing the main window.

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

@@ -54,10 +54,6 @@ public class VaultListController implements FxController {
 				if (c.wasAdded()) {
 					Vault anyAddedVault = c.getAddedSubList().get(0);
 					vaultList.getSelectionModel().select(anyAddedVault);
-					window.setIconified(false);
-					window.show();
-					window.toFront();
-					window.requestFocus(); // TODO: this beeps on macOS if there is a modal child window...
 				}
 			}
 		});