Fix log format string quotation in nginx config

What does this MR do?

Fix log format string quotation in nginx config

If the log format is not enclosed in 'single quotes' the spaces inside the log format are ignored (syntactical whitespace). The "double quotes" are then interpreted, meaning the spaces inside "double quotes" work but the quotes themselves are not actually output to the log files.

See also the "log_format combined" predefinition in nginx docs. https://nginx.org/en/docs/http/ngx_http_log_module.html#log_format

The $gzip_ratio suffix is no longer in use in GitLab lib/support/nginx, so remove it to fully synchronise the format string to Omnibus config.

Related issues

This is a straight port of gitlab!119707 (merged) for Omnibus configuration, as requested by the comment in lib/support/nginx/gitlab to update it here as well.

Checklist

See Definition of done.

For anything in this list which will not be completed, please provide a reason in the MR discussion.

Required

• MR title and description are up to date, accurate, and descriptive.
• MR targeting the appropriate branch.
• Latest Merge Result pipeline is green.
• When ready for review, MR is labeled "~workflow::ready for review" per the Distribution MR workflow.

For GitLab team members

If you don't have access to this, the reviewer should trigger these jobs for you during the review process.

• The manual Trigger:ee-package jobs have a green pipeline running against latest commit.
• If config/software or config/patches directories are changed, make sure the build-package-on-all-os job within the Trigger:ee-package downstream pipeline succeeded.
• If you are changing anything SSL related, then the Trigger:package:fips manual job within the Trigger:ee-package downstream pipeline must succeed.
• If CI configuration is changed, the branch must be pushed to dev.gitlab.org to confirm regular branch builds aren't broken.

Expected (please provide an explanation if not completing)

• Test plan indicating conditions for success has been posted and passes.
• Documentation created/updated.
• Tests added.
• Integration tests added to GitLab QA.
• Equivalent MR/issue for the GitLab Chart opened.
• Validate potential values for new configuration settings. Formats such as integer 10, duration 10s, URI scheme://user:passwd@host:port may require quotation or other special handling when rendered in a template and written to a configuration file.