Make the init.d script's output refer to "GitLab CI" instead of "GitLab".
Refer to "GitLab CI" in some additional places in the init.d script.
Suppress success output if "rake schedule_builds" is called with the "--silent" flag.

"verbose" in schedule_builds.rake is synonymous to Rake.verbose,
which is set to false if Rake is called with the flags "--quiet" or "--silent".