Swapped a literal equals to InvariantEquals (to handle case-sensitivity)

Author: leekelleher

src/Our.Umbraco.DocTypeGridEditor/Helpers/DocTypeGridEditorHelper.cs

@@ -78,7 +78,7 @@ private static IPublishedContent ConvertValue(string id, string contentTypeAlias
                         /* Now that we have the DB stored value, we actually need to then convert it into it's
                          * XML serialized state as expected by the published property by calling ConvertDbToString
                          */
-                        var propType2 = contentType.CompositionPropertyTypes.Single(x => x.Alias == propType.PropertyTypeAlias);
+                        var propType2 = contentType.CompositionPropertyTypes.Single(x => x.Alias.InvariantEquals(propType.PropertyTypeAlias));
 
                         Property prop2 = null;
                         try