add localized message if username/password is wrong

src/BreCalClient/MainWindow.xaml.cs

@@ -133,7 +133,10 @@ namespace BreCalClient
             {
                 if ((ex.ErrorContent != null && ((string)ex.ErrorContent).StartsWith("{"))) {
                     Error? anError = JsonConvert.DeserializeObject<Error>((string)ex.ErrorContent);
-                    this.labelLoginResult.Content = anError?.Message ?? ex.Message;
+                    if ((anError != null) && anError.Message.Equals("invalid credentials"))
+                        this.labelLoginResult.Content = BreCalClient.Resources.Resources.textWrongCredentials;
+                    else
+                        this.labelLoginResult.Content = anError?.Message ?? ex.Message;
                 }
                 else {
                     this.labelLoginResult.Content = ex.Message;

src/BreCalClient/Resources/Resources.Designer.cs

@@ -940,6 +940,15 @@ namespace BreCalClient.Resources {
             }
         }
         
+        /// <summary>
+        ///   Looks up a localized string similar to Wrong username or password.
+        /// </summary>
+        public static string textWrongCredentials {
+            get {
+                return ResourceManager.GetString("textWrongCredentials", resourceCulture);
+            }
+        }
+        
         /// <summary>
         ///   Looks up a localized string similar to Zone entry.
         /// </summary>

src/BreCalClient/Resources/Resources.de.resx

@@ -415,4 +415,7 @@
   <data name="textPhone" xml:space="preserve">
     <value>Telefon</value>
   </data>
+  <data name="textWrongCredentials" xml:space="preserve">
+    <value>Benutzername / Passwort falsch</value>
+  </data>
 </root>

src/BreCalClient/Resources/Resources.resx

@@ -406,6 +406,9 @@
   <data name="textWidth" xml:space="preserve">
     <value>Width</value>
   </data>
+  <data name="textWrongCredentials" xml:space="preserve">
+    <value>Wrong username or password</value>
+  </data>
   <data name="textZoneEntryTime" xml:space="preserve">
     <value>Zone entry</value>
   </data>