Ensure NGINX repo and install on nginx_hosts before apt update, so that
the latest NGINX key is deployed and apt update won't fail on an invalid
signature on these hosts.
Also only run the gnupg install if gnupg isn't present in the nginx
repo_setup.yaml to make that work.
Somewhere between ansible [core 2.14.4] and ansible [core 2.15.0] the
logic for the distribution_version Ansible fact got changed. With the
newer Ansible version Debians distribution_version gets reported as 11.7
as opposed to getting reported as 11 with the old Ansible version. To
still allow for useful distribution checks, extend the
distribution_check role by allowing the specification of
distribution_major_versions and distribution_releases as well.
This way you can check for an Ubuntu version by using
distribution_version (which for example resolves to 18.04, while
distribution_major_version would resolve to 18 in that case) and check
for a Debian version by using distribution_major_version (which for
example resolves to 11, while distribution_version would resolve to 11.7
in that case).
