message: [Core] Remove extra check in UpdateTime
  UpdateTime is called only for PoW blocks, no need to check for
  TimeProtoV2
diff: @@ -92,11 +92,7 @@ public:
  void UpdateTime(CBlockHeader* pblock, const CBlockIndex* pindexPrev)
  {
  - if (Params().IsTimeProtocolV2(pindexPrev->nHeight+1)) {
  - pblock->nTime = GetCurrentTimeSlot();
  - } else {
  pblock->nTime = std::max(pindexPrev->GetMedianTimePast() + 1, GetAdjustedTime());
  - }
  // Updating time can change work required on testnet:
  if (Params().AllowMinDifficultyBlocks())
  @@ -742,6 +738,7 @@ void BitcoinMiner(CWallet* pwallet, bool fProofOfStake)
  // Changing pblock->nTime can change work required on testnet:
  hashTarget.SetCompact(pblock->nBits);
  }
  +
  }
  }
  }
  