add a field

AccountMeta add a field IsContract

Author: chenyanchen

golang/iotextypes/blockchain.pb.go

@@ -100,4 +100,5 @@ message AccountMeta {
   uint64 nonce = 3;
   uint64 pendingNonce = 4;
   uint64 numActions = 5;
+  bool isContract = 6;
 }