Merge pull request #2751 from lkoruba/hackathon-use-logger-warn-with-func

(V8 Hackathon) use logger warn with func<string>

src/Umbraco.Web/PublishedCache/XmlPublishedCache/DictionaryPublishedContent.cs

@@ -108,7 +108,7 @@ namespace Umbraco.Web.PublishedCache.XmlPublishedCache
                 else
                 {
                     // this is a property that does not correspond to anything, ignore and log
-                    Current.Logger.Warn<PublishedMediaCache>("Dropping property \"" + i.Key + "\" because it does not belong to the content type.");
+                    Current.Logger.Warn<PublishedMediaCache>(() => "Dropping property \"" + i.Key + "\" because it does not belong to the content type.");
                 }
             }
         }