roundcube: don't hard-code nginx user in service

        upload_max_filesize = ${cfg.maxAttachmentSize}

      '';

      settings = lib.mapAttrs (name: lib.mkDefault) {

        "listen.owner" = "nginx";

        "listen.group" = "nginx";

        "listen.owner" = config.services.nginx.user;

        "listen.group" = config.services.nginx.group;

        "listen.mode" = "0660";

        "pm" = "dynamic";

        "pm.max_children" = 75;