Fix wrong user pass

lib/providers/auth.dart

@@ -120,7 +120,7 @@ class Auth with ChangeNotifier {
     );
     final responseData = json.decode(response.body);
     print(responseData);
-    if (response.statusCode == 401) {
+    if (response.statusCode == 400) {
       if (responseData['message'] == 'The user credentials were incorrect.') {
         return 'badinput'; // incorrect user or pass
       } else {