Binance memo flag filter checks the wrong field

Bifrost filters incoming Binance transactions if the destination address has the memo flag set. For swaps it is pulling the wrong field from the memo (limit instead of destination) to check for a thorname alias:

https://gitlab.com/thorchain/thornode/-/blob/35d1a7014cd42a4a57db623a986581df7cd772b1/bifrost/observer/observe.go#L340-344

It should be using parts[2] instead of parts[3].

https://docs.thorchain.org/developers/transaction-memos

SWAP:ASSET:DESTADDR:LIM