message: Add description for -pivstake= and -zpivstake=.
diff: @@ -507,6 +507,8 @@ std::string HelpMessage(HelpMessageMode mode)
  #ifdef ENABLE_WALLET
  strUsage += HelpMessageGroup(_("Staking options:"));
  strUsage += HelpMessageOpt("-staking=<n>", strprintf(_("Enable staking functionality (0-1, default: %u)"), 1));
  + strUsage += HelpMessageOpt("-pivstake=<n>", strprintf(_("Enable or disable staking functionality for PIV inputs (0-1, default: %u)"), 1));
  + strUsage += HelpMessageOpt("-zpivstake=<n>", strprintf(_("Enable or disable staking functionality for zPIV inputs (0-1, default: %u)"), 1));
  strUsage += HelpMessageOpt("-reservebalance=<amt>", _("Keep the specified amount available for spending at all times (default: 0)"));
  if (GetBoolArg("-help-debug", false)) {
  strUsage += HelpMessageOpt("-printstakemodifier", _("Display the stake modifier calculations in the debug.log file."));
  