I don't know what's the connection between Gnome Commander and mc, but what I _do_ know is that I'll never install gcmd. Why?
1)mc is exactly what I need (though that message is very irritating)
2)since it's called Gnome Commander, to run it, you'll need the gnome libraries...well, I don't like it
3)I hate GUI (it should be probably the first reason)
"If you like to get in contact with us behind the project, then you can drop a mail to one of our mailing lists or contact the developers above directly."
I found a mail in which the developer was explaining that's not possible to disable it.