simplify the extraction of transactionID from Transaction object

Author: ckeshava

src/ripple/rpc/handlers/AccountTx.cpp

@@ -333,8 +333,7 @@ populateJsonResponse(
                             JsonOptions::include_date |
                                 JsonOptions::disable_API_prior_V2,
                             false);
-                        jvObj[jss::hash] = to_string(
-                            txn->getSTransaction()->getTransactionID());
+                        jvObj[jss::hash] = to_string(txn->getID());
                         jvObj[jss::ledger_index] = txn->getLedger();
                         jvObj[jss::ledger_hash] =
                             to_string(context.ledgerMaster.getHashBySeq(

src/ripple/rpc/handlers/Tx.cpp

@@ -349,8 +349,7 @@ populateJsonResponse(
             if (result.ledgerHash)
                 response[jss::ledger_hash] = to_string(*result.ledgerHash);
 
-            response[jss::hash] =
-                to_string(result.txn->getSTransaction()->getTransactionID());
+            response[jss::hash] = to_string(result.txn->getID());
             if (result.validated)
             {
                 response[jss::ledger_index] = result.txn->getLedger();

src/ripple/rpc/impl/TransactionSign.cpp

@@ -654,8 +654,7 @@ transactionFormatResultImpl(Transaction::pointer tpTrans, unsigned apiVersion)
         {
             jvResult[jss::tx_json] =
                 tpTrans->getJson(JsonOptions::disable_API_prior_V2);
-            jvResult[jss::hash] =
-                to_string(tpTrans->getSTransaction()->getTransactionID());
+            jvResult[jss::hash] = to_string(tpTrans->getID());
         }
         else
             jvResult[jss::tx_json] = tpTrans->getJson(JsonOptions::none);