Merge pull request tronprotocol#2289 from tronprotocol/Hotfix/removeAbiJson

remove abiString

Author: BlueHoopor

src/main/java/org/tron/common/logsfilter/trigger/ContractTrigger.java

@@ -79,8 +79,4 @@ public class ContractTrigger extends Trigger {
   @Getter
   @Setter
   private ABI abi;
-
-  @Getter
-  @Setter
-  private String abiString;
 }