message: Remove redundant nStakeMinAge check
  Minimum coin age for staking is only relevant for PoSv2 but in CheckStakeKernelHash() this was not considered
diff: @@ -662,9 +662,6 @@ static inline bool CheckStakeKernelHashV2(CStakeModifier* pStakeMod, unsigned in
  if (nTimeTx < txPrev.nTime) // Transaction timestamp violation
  return error("CheckStakeKernelHash() : nTime violation");
  - if (nTimeBlockFrom + nStakeMinAge > nTimeTx) // Min age requirement
  - return error("CheckStakeKernelHash() : min age violation");
  -
  // Base target
  CBigNum bnTarget;
  bnTarget.SetCompact(nBits);
  