Handle command cancelling

xmpp/handlers.go

@@ -760,6 +760,12 @@ func handleSetQueryCommand(s xmpp.Sender, iq *stanza.IQ, command *stanza.Command
 				} else {
 					cmdString = "/" + command.Node
 				}
+			} else if command.Action == stanza.CommandActionCancel {
+				answer.Payload = &stanza.Command{
+					SessionId: command.Node,
+					Node:      command.Node,
+					Status:    stanza.CommandStatusCancelled,
+				}
 			}
 		}
 	}