message: Use PoS key rather than reserve key script when populating block
diff: @@ -1130,7 +1130,7 @@ void ThreadStakeMiner(CWallet *pwallet)
  SetThreadPriority(THREAD_PRIORITY_ABOVE_NORMAL);
  // Create a block that's properly populated with transactions
  std::unique_ptr<CBlockTemplate> pblocktemplatefilled(
  - BlockAssembler(Params()).CreateNewBlock(reservekey.reserveScript, true, &nTotalFees,
  + BlockAssembler(Params()).CreateNewBlock(pblock->vtx[1]->vout[1].scriptPubKey, true, &nTotalFees,
  i, FutureDrift(GetAdjustedTime()) - STAKE_TIME_BUFFER));
  if (!pblocktemplatefilled.get())
  return;
  