Fix handling of "{" in string values

src/AddIns/DisplayBindings/WpfDesign/WpfDesign.XamlDom/Project/XamlTextValue.cs

@@ -48,6 +48,8 @@ namespace ICSharpCode.WpfDesign.XamlDom
 		internal XamlTextValue(XamlDocument document, string textValue)
 		{
 			this.document = document;
+			if (textValue.StartsWith("{"))
+				textValue = "{}" + textValue;
 			this.textValue = textValue;
 		}