Update NPM version to 2.10.4

[jc21]

See https://github.com/NginxProxyManager/nginx-proxy-manager/releases/tag/v2.10.4

[jc21]

Hi Team, it would be nice if I could edit the docker image tag for apps in the UI. I was hoping to have the docker image be something like

image: jc21/nginx-proxy-manager:${AppVersion:-2.10.4}

however, this requires that the AppVersion variable be configurable from the interface. Is this something that can be achieved currently?

[ETWang1991]

We will provide the installation of custom labels in a later version