message: [Cleanup][RPC] remove extra "modifier" and "modifierV2" fields
  There is already a "stakeModifier" attribute for PoS blocks
diff: @@ -133,9 +133,6 @@ UniValue blockToJSON(const CBlock& block, const CBlockIndex* blockindex, bool tx
  if (pnext)
  result.push_back(Pair("nextblockhash", pnext->GetBlockHash().GetHex()));
  - result.push_back(Pair("modifier", strprintf("%016x", blockindex->GetStakeModifierV1())));
  - result.push_back(Pair("modifierV2", blockindex->GetStakeModifierV2().GetHex()));
  -
  result.push_back(Pair("moneysupply",ValueFromAmount(blockindex->nMoneySupply)));
  UniValue zpivObj(UniValue::VOBJ);
  