Update of Nginx in containers

[msvihra]

The containers, serving LA websites should use latest stable Nginx version available which is nginx-1.20.2 at the time of writing.

[msvihra]

Since Nginx on < 1.20.1 versions suffers various bugs and security problems, version used in LiveAgent-Docker need to be upgraded to latest version (1.20.2).

Proposed solution:

• Build RPM of Nginx from latest stable source and add all required modules which are - lua, redis2, push-stream to Nginx used in this environment. RPM will be built on devel VM, using this state, since same method was used on currently used version (1.15.8).
• Add new RPM to repo and modify installation paths to match this. This need to be modified in all variations - docker-1_host and both LBs used in docker-4_hosts_2LB.
• Remove unused RPMs after.

What need to be tested:

• Nginx containers provisioning.
• Liveagent installation and basic functionality using new Nginx (visitors, events, pagevisits, chats, etc).
• Test containers upgrade.

Deliverables:

• One PR adding upgraded Nginx version to all variations, closing issue.

ETA:

• 8 hours for PR and test.

[lubo]

Approved.