Call correct overload of log.FatalAsync
Call correct overload of log.FatalAsync

The method was previously hitting `FatalSync(string message, params object[] args)` and thereby throwing away the exception object as it wasn't referenced in the message. The change ensures that `FatalSync(string message, Exception ex)` is hit and the exception information is logged correctly.
thomasgalliker/MetroLog,mbrit/MetroLog,mbrit/MetroLog,thomasgalliker/MetroLog,onovotny/MetroLog,thomasgalliker/MetroLog,onovotny/MetroLog,onovotny/MetroLog,mbrit/MetroLog