nixos/nextcloud-notify_push: turn off keepalive_timeout, proxy_buffering (#364937)

          proxyPass = "http://unix:${cfg.socketPath}";

          proxyWebsockets = true;

          recommendedProxySettings = true;

          extraConfig = # nginx

            ''

              # disable in case it was configured on a higher level

              keepalive_timeout 0;

              proxy_buffering off;

            '';

        };

      }