CommandEvent.Reply: Send all messages to management room

Because the Bridge Bot doesn't participate in the rooms it can't send any
messages to this room. Hence, we should send all replies to the management
room.

commands.go

@@ -52,7 +52,7 @@ type CommandEvent struct {
 
 // Reply sends a reply to command as notice
 func (ce *CommandEvent) Reply(msg string) {
-	_, err := ce.Bot.SendNotice(string(ce.RoomID), msg)
+	_, err := ce.Bot.SendNotice(string(ce.User.ManagementRoom), msg)
 	if err != nil {
 		ce.Handler.log.Warnfln("Failed to reply to command from %s: %v", ce.User.MXID, err)
 	}