[IMPLEMENTED] Cancelling gates

[Dokhu]

To stay on the "Gate Management" page of the airport where I'm trying to delete the gates partially or totally to avoid searching the airport again in a long list and start the whole process every time I cancel a gate. It takes a lot of time. I'm really sorry Admin if I'm not able to explain but try to cancel ten gates in a long list of airports and you will see what I mean.

Thanks for your patience and good work.