Fix bithumb fetchBalance Fix regression from https://github.com/ccxt/ccxt/commit/d9805555b0dba5d33979a1beb65eeca149f53cae [ci skip]
Fix bithumb fetchBalance Fix regression from https://github.com/ccxt/ccxt/commit/d9805555b0dba5d33979a1beb65eeca149f53cae [ci skip]