log tail output is broken with for example log tail 200

[Vaelor]

There seems to be an Issue in the function that splits up the message parts.
https://github.com/Vaelor/errbot-mattermost-backend/blob/master/mattermost.py#L450

This is not very high on my TODO list honestly, since the output isn't very readable at all in my opinion and I found myself using that feature very rarely.

[Vaelor]

It is broken differently...