Avoid passing through the {OriginalFormat} property

Author: nblumhardt

src/Serilog.Framework.Logging/SerilogLogger.cs

@@ -75,8 +75,10 @@ public void Log(LogLevel logLevel, int eventId, object state, Exception exceptio
                     {
                         messageTemplate = (string)property.Value;
                     }
-
-                    logger = logger.ForContext(property.Key, property.Value);
+                    else
+                    {
+                        logger = logger.ForContext(property.Key, property.Value);
+                    }
                 }
 
                 var stateType = state.GetType();