message: add help for regeneratemintpool
diff: @@ -2654,6 +2654,11 @@ UniValue fundrawtransaction(const UniValue& params, bool fHelp)
  UniValue regeneratemintpool(const UniValue &params, bool fHelp) {
  + if (fHelp || params.size() > 0)
  + throw runtime_error(
  + "regeneratemintpool\n"
  + "\nIf issues exist with the keys that map to mintpool entries in the DB, this function corrects them.\n"
  + );
  if (pwalletMain->IsLocked())
  throw JSONRPCError(RPC_WALLET_UNLOCK_NEEDED,
  "Error: Please enter the wallet passphrase with walletpassphrase first.");
  