message: Fix rpc help message and namespace issue
diff: @@ -2720,7 +2720,7 @@ UniValue mint(const UniValue& params, bool fHelp)
  "\nAutomatically choose denominations to mint by amount."
  + HelpRequiringPassphrase() + "\n"
  "\nArguments:\n"
  - "1. \"amount\" (numeric or string, required) The amount in " + CURRENCY_UNIT + " to mint but must not less than 0.1\n"
  + "1. \"amount\" (numeric or string, required) The amount in " + CURRENCY_UNIT + " to mint, must be a multiple of 0.1\n"
  "\nResult:\n"
  "\"transactionid\" (string) The transaction id.\n"
  "\nExamples:\n"
  @@ -3202,7 +3202,7 @@ UniValue spendmany(const UniValue& params, bool fHelp) {
  LOCK2(cs_main, pwalletMain->cs_wallet);
  // Only account "" have sigma coins.
  - string strAccount = AccountFromValue(params[0]);
  + std::string strAccount = AccountFromValue(params[0]);
  if (!strAccount.empty())
  throw JSONRPCError(RPC_WALLET_INSUFFICIENT_FUNDS, "Account has insufficient funds");
  