[DRE-maint] open-build-service is marked for autoremoval from testing

[Debian testing autoremoval watch]

open-build-service 2.7.4-2 is marked for autoremoval from testing on 2017-09-02

It (build-)depends on packages with these RC bugs:
869034: ruby-combustion: FTBFS: ERROR: Test "ruby2.3" failed.
869038: ruby-rspec-rails: FTBFS: ERROR: Test "ruby2.3" failed.
869039: ruby-kaminari: FTBFS: ERROR: Test "ruby2.3" failed.
869044: ruby-sass-rails: FTBFS: ERROR: Test "ruby2.3" failed.
869050: ruby-jquery-rails: FTBFS: ERROR: Test "ruby2.3" failed: Invalid gemspec in [jquery-rails.gemspec]: No such file or directory - git