Univention Matterbridge app

1.11.3

• implements Matterbridge v.1.11.3

1.11.1

• implements Matterbridge v.1.11.1
• remove slash from the end of the Mattermost url in preinst step

1.11.0

• implements Matterbridge v.1.11.0
• requires Mattermost app 5.1.0 for automatic configuration