Fix sshd startup errors upon a full Docker restart

Merged Stan Hu requested to merge sh-fix-restart-docker-sshd into master

To reproduce:

  1. Install GitLab via a Docker image
  2. Run docker restart gitlab

Startup fails with:

Preparing services...
ln: failed to create symbolic link '/opt/gitlab/init/sshd': File exists

To fix this, just use ln -sf.

Closes #2371 (closed)

Edited by GitLab Release Tools Bot