MainWindow: Fix crash on closing, when other window is in editing or creating mode

Elwig/Windows/AdministrationWindow.cs

@@ -19,14 +19,14 @@ namespace Elwig.Windows {
 
         private bool _isEditing;
         private bool _isCreating;
-        protected bool IsEditing {
+        public bool IsEditing {
             get { return _isEditing; }
             set {
                 _isEditing = value;
                 LockContext = IsEditing || IsCreating;
             }
         }
-        protected bool IsCreating {
+        public bool IsCreating {
             get { return _isCreating; }
             set {
                 _isCreating = value;