add contract listner exception

Helius

2022-07-22 823aabb391a0cbd2eddf7c58c03b76e71967b964

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

@@ -24,4 +24,6 @@
    BigInteger blockNumber();

    BigInteger totalSupply();

    String safeMintNFT(String toAddress);
}