Have FromArtifact return string not JObject

Author: mattbrailsford

src/Umbraco.Commerce.Deploy/Connectors/ValueConnectors/UmbracoCommerceVariantsEditorValueConnector.cs

@@ -72,7 +72,7 @@ public override object FromArtifact(string value, IPropertyType propertyType, ob
                 result.Content = FromArtifact(result.Content, propertyEditorAliases, contextCache).ToList();
                 result.Settings = FromArtifact(result.Settings, propertyEditorAliases, contextCache).ToList();
 
-                return JObject.FromObject(result);
+                return JsonConvert.SerializeObject(result, Formatting.None);
             }
 
             return null;