Secrets should not be given on command line

When using the authorization feature of gitlab pages, gitlab-pages requires secrets to be given on the command line

  -auth-client-id string
        GitLab application Client ID
  -auth-client-secret string
        GitLab application Client Secret
  -auth-secret string
        Cookie store hash key, should be at least 32 bytes long.

This is securitywise very bad resp. a total no-go. There should be used files (like for -admin-secret-path) to store such variables.