message: net: correctly initialize nMinPingUsecTime
  `nMinPingUsecTime` was left uninitialized in CNode.
  The correct initialization for a minimum-until-now is int64_t's max value, so initialize it to that.
  Thanks for noticing.
diff: @@ -2401,6 +2401,7 @@ CNode::CNode(SOCKET hSocketIn, CAddress addrIn, std::string addrNameIn, bool fIn
  nPingUsecStart = 0;
  nPingUsecTime = 0;
  fPingQueued = false;
  + nMinPingUsecTime = std::numeric_limits<int64_t>::max();
  {
  LOCK(cs_nLastNodeId);
  