gitlab workflow template fixes #2401

[sudhirrs]

This fixes the gitlab templates. There is one other aspect that is relevant for gitlab self hosted users and not changed in this. The host keys need to point to their host

      ssh-keyscan -H 'gitlab.com' >> ~/.ssh/known_hosts
      ssh-keyscan gitlab.com | sort -u - ~/.ssh/known_hosts -o ~/.ssh/known_hosts

I applicable, I acknowledge that I have:

• Read the contributing guide
• Ran terraform fmt on all modified files
• Regenerated the relevant README.md files using tools/tfdoc.py
• Made sure all relevant tests pass