[IMPROVE] adding support for custom ZLIB and PCRE build

Hello,

awesome job with this script.
I wondered if you would be interested in a PR to be able to build Nginx with custom/latest PCRE and Zlib libs?

`--with-zlib=`
`--with-pcre=`

I usually set those in my configure option. It's almost the same process as for openSSL: git clone, configure, make.

I just want to know if it's useful or not, as maybe there's a good reason those are not specified.

Thanks

EDIT: related to https://github.com/angristan/nginx-autoinstall/issues/176 - may be nice to be able to specify official zlib version, or custom (Cloudflare) one.