How can I remove Teams from Gitlab Mattermost

That makes sense, thanks for that explanation. So the error message is a bit misleading but I can see where this is coming from.

Now I'm going to /opt/gitlab/embedded/service/mattermost/i18n and call sudo /opt/gitlab/embedded/bin/mattermost -version -config="/var/opt/gitlab/mattermost/config.json" getting another error:

[13:25:54 CET 2016/03/24] [INFO] (github.com/mattermost/platform/utils.GetTranslationsBySystemLocale:52) Loaded system translations for 'en' from '/opt/gitlab/embedded/service/mattermost/i18n/en.json'
[2016/03/24 13:25:54 CET] [CRIT] Failed to ping db err:pq: Peer authentication failed for user "gitlab_mattermost"
panic: Failed to open sql connection pq: Peer authentication failed for user "gitlab_mattermost"

goroutine 1 [running]:
panic(0xb2e0c0, 0xc820431c60)
	/usr/local/go/src/runtime/panic.go:464 +0x3e6
github.com/mattermost/platform/store.setupConnection(0xd40f40, 0x6, 0xc820430bf0, 0x8, 0xc820060ae0, 0x5d, 0xa, 0xa, 0x419600, 0x10)
	/var/lib/jenkins/jobs/mattermost-platform-release/workspace/src/github.com/mattermost/platform/store/sql_store.go:169 +0x894
github.com/mattermost/platform/store.NewSqlStore(0x0, 0x0)
	/var/lib/jenkins/jobs/mattermost-platform-release/workspace/src/github.com/mattermost/platform/store/sql_store.go:61 +0x122
github.com/mattermost/platform/api.NewServer()
	/var/lib/jenkins/jobs/mattermost-platform-release/workspace/src/github.com/mattermost/platform/api/server.go:35 +0xe8
main.main()
	/var/lib/jenkins/jobs/mattermost-platform-release/workspace/src/github.com/mattermost/platform/mattermost.go:67 +0x756