On errors with sigining up and renewing there are only log entries,
and mod-md is retrying in a loop.
Now the MDNotifyCmd is only triggered when it is ok, seems logical
also notify when there is some wrong.
Use MDNotifyCmd for the first error AH10057 and it should be nice with
the description of the error (AH10056 and (20014)Internal error ....)
So the users can be notified by mail or whatever action they want from
Current docu MDNotifyCmd :