Use same pattern for form validation

dashboard/src/components/AppImportDialog.vue

@@ -10,7 +10,6 @@ import { REGIONS_CONTABO, REGIONS_VULTR, REGIONS_IONOS, REGIONS_OVH, REGIONS_LIN
 const appsModel = AppsModel.create();
 
 const dialog = useTemplateRef('dialog');
-const form = useTemplateRef('form');
 const backupConfigInput = useTemplateRef('backupConfigInput');
 const appId = ref('');
 const busy = ref(false);
@@ -24,6 +23,7 @@ const encryptionPasswordHint = ref('');
 const encryptionPassword = ref('');
 const encryptedFilenames = ref(false);
 
+const form = useTemplateRef('form');
 const isFormValid = ref(false);
 function checkValidity() {
   isFormValid.value = form.value ? form.value.checkValidity() : false;
@@ -279,6 +279,8 @@ defineExpose({
     encryptionPasswordHint.value = '';
 
     dialog.value.open();
+
+    setTimeout(checkValidity, 100); // update state of the confirm button
   }
 });