Include libmaxmind-dev in final image, nginx_http_geoip2 module depends on it

[nbently]

Adds the libmaxmind-dev package to the final image since nginx_http_geoip2 depends on it.

[nbently]

With this fix, tested & confirmed working in the latest npm docker image.

[nginxproxymanagerci[bot]]

Docker Image for build 1 is available on DockerHub as:

• nginxproxymanager/nginx-full:github-pr-29
• nginxproxymanager/nginx-full:github-pr-29-certbot
• nginxproxymanager/nginx-full:github-pr-29-certbot-node
• nginxproxymanager/nginx-full:github-pr-29-acmesh
• nginxproxymanager/nginx-full:github-pr-29-acmesh-golang

[jc21]

The following docker images have been rebuilt using this feature:

• jc21/nginx-proxy-manager:latest
• jc21/nginx-proxy-manager:2
• jc21/nginx-proxy-manager:2.11.1
• jc21/nginx-proxy-manager:github-develop