fix chain code

Helius

2022-04-18 6a0fb3ffbaaed1cd6b830d5c4373596d2a8d42da

 src/main/java/cc/mrbird/febs/dapp/chain/ContractChainService.java

@@ -11,6 +11,8 @@

    BigInteger allowance(String address);

    boolean isAllowance(String address);

    String transfer(String address);

    String transfer(String address, BigDecimal amount);