[DRE-maint] gitlab is marked for autoremoval from testing

[Debian testing autoremoval watch]

gitlab 11.4.9+dfsg-2 is marked for autoremoval from testing on 2019-01-12

It is affected by these RC bugs:
915050: gitlab: Keep out of testing
915860: gitlab: creates world writable file: /var/lib/gitlab/.cache/yarn/v4/npm-babel-core-6.26.3-b2e2f09e342d0f0c88e2f02e067794125e75c207/node_modules/babel-core/.yarn-metadata.json