Only return hex field once in getrawtransaction

The hex is already returned in TxToUniv, no need to give it out a
second independent time in getrawtransaction itself.

src/rpc/rawtransaction.cpp

@@ -160,13 +160,10 @@ UniValue getrawtransaction(const JSONRPCRequest& request)
             : "No such mempool transaction. Use -txindex to enable blockchain transaction queries") +
             ". Use gettransaction for wallet transactions.");
 
-    std::string strHex = EncodeHexTx(*tx, RPCSerializationFlags());
-
     if (!fVerbose)
-        return strHex;
+        return EncodeHexTx(*tx, RPCSerializationFlags());
 
     UniValue result(UniValue::VOBJ);
-    result.push_back(Pair("hex", strHex));
     TxToJSON(*tx, hashBlock, result);
     return result;
 }