mmrepquota -u not available in the exporter

[creativefre]

Hello,

For the mmrepquota the exporter only executes the -j parameter. For our use case we also want to quota of the users so with the -u parameter.

Is it possible to add this functionality to your exporter?

Thank you.

[treydock]

I think I can add that as an opt-in collector.

[treydock]

Fixed by #59