Better identify who has been rejected by mmsd

[mpejcoch]

2021/03/12 07:57:44 Unauthorized: API key not accepted
2021/03/12 07:58:42 Unauthorized: API key not accepted

Today only this is listed in the mmsd log, would be nice to see something more to check whether there might be clients with problems.

[vkbo]

Hmm, clients are only identified by their key, so an invalid key would not connect the call to a known client. The database is update on a successful usage of a valid API key, but there is currently no way to store invalid posts.

The command line client will receive the error code from the daemon, so isn't it better handled on that side? For the py-mms wrapper we could raise an exception.

[mpejcoch]

I was thinking about some metadata about the client, e.g. version number and IP address.