fix admin add and update

lib/models/admin_form_data.dart

@@ -34,4 +34,13 @@ class AdminFormData {
         locked: admin.locked,
         expires: admin.expires,
       );
+
+  Admin get toAdmin => Admin(
+        expires: expires,
+        firstName: firstName,
+        lastName: lastName,
+        login: login,
+        locked: locked,
+        service: service,
+      );
 }

lib/pages/admin_details/admin_details_page.dart

@@ -257,7 +257,7 @@ class _AdminDetailsPageState extends State<AdminDetailsPage> {
 
   void _onSave() async {
     _showSaving();
-    adminsBloc.onUpdateAdmin(_admin);
+    adminsBloc.onUpdateAdmin(_formData.toAdmin.copyWith(id: _admin.id));
   }
 
   Future<void> _showSaving() async {

lib/pages/admin_list/add_admin_dialog.dart

@@ -30,6 +30,7 @@ class _AddAdminDialogState extends State<AddAdminDialog> {
               width: 196.0,
               child: TextFormField(
                 validator: onValidateUsername,
+                onChanged: (String input) => _data.login = input,
               ),
             ),
           ),