[GitLab CE] Redirect URI issue about integram

[Blasterdick]

UPD:

1. The Redirect URL should be like this: http(s)//sub.domain.com:port/auth/gitlab
2. INTEGRAM_BASE_URL should be a complete FQDN (not an IP), ACCESSIBLE THROUGH THE INTERNET, so Telegram could open the links to it. Like http(s)//sub.domain.com:port
3. It doesn't really matter what scopes do you use in Application settings on GitLab (they're added to a GET request by Integram anyways).
4. INTEGRAM_PORT have to be pointed as well.

After that, everything works like a charm. Thanks, @requilence.