feat: support disabling worker_rlimit_nofile

[DoctorFTB]

Pull Request (PR) description

Add support for disabling "worker_rlimit_nofile" by checking for a value greater than zero

This Pull Request (PR) fixes the following issues

Fixes #1611

[kenyon]

This seems OK, but I think it would be better if it defaulted to undef, so that you don't have to specify a special value to disable it. I guess that would be a breaking change though. Not sure why the default is 1024 when there is no default upstream: https://nginx.org/en/docs/ngx_core_module.html#worker_rlimit_nofile

[DoctorFTB]

This seems OK, but I think it would be better if it defaulted to undef, so that you don't have to specify a special value to disable it. I guess that would be a breaking change though. Not sure why the default is 1024 when there is no default upstream: https://nginx.org/en/docs/ngx_core_module.html#worker_rlimit_nofile

Yeah! This module has not a little options with values ​​different from the default values ​​in the nginx docs.

For example:
name -> current module vs nginx docs
keepalive_timeout -> 65s vs 75s
keepalive_requests -> 100 vs 1000
client_max_body_size -> 10m vs 1m

Also has a default value as value, not as undef, like options: client_body_timeout, send_timeout

May be its best practice or .. ?