problem when channel's name contains space or caps

[phineas0fog]

Hello,
The plugin seems to don't work if mattermost channel name contains space caps or underscore.

[nixjobin]

Just replace the space with a -

Basically, you can click on the Mattermost channel Info, and copy the ending slug in the URL field.

Ie, If the URL is showing https://your-mattermost-url/ab/channels/project-name-here then you can use project-name-here in the Mattermnost Channel field in Redmine