Currently, it seems there is no easy way to override package to add
modules. For example, if we want to add the `ipscrub` module, we can
do:
pkgs.nginxStable.override {
modules = [ pkgs.nginxModules.ipscrub ];
};
But, then, we loose `rtmp`, `dav` and `moreheaders` which are defined
in `all-packages.nix`. With this modification, we can now do:
pkgs.nginxStable.override {
modules = pkg.nginxStable.passthru.modules ++ [ pkgs.nginxModules.ipscrub ];
};