call PasswordBoxOnPasswordChanged after initialization

to support passwordboxes which are initially not empty
fixes #213

Author: campersau

MaterialDesignThemes.Wpf/PasswordFieldAssist.cs

@@ -23,7 +23,8 @@ private static void ManagedPropertyChangedCallback(DependencyObject dependencyOb
             if (passwordBox != null)
             {
                 passwordBox.PasswordChanged += PasswordBoxOnPasswordChanged;
-                ConfigureHint(passwordBox);
+                // call listener immediately, maybe passwordbox was not empty
+                PasswordBoxOnPasswordChanged(passwordBox, new RoutedEventArgs());
             }
         }
 
@@ -89,10 +90,5 @@ public static bool GetIsNullOrEmpty(DependencyObject element)
             return (bool)element.GetValue(IsNullOrEmptyProperty);
         }
     }
-
-    public static class ProgressBarAssist
-    {
-
-
-    }
+    
 }