EDITED 2019-02-08

`maxTxFee` is a global variable, used by both the raw transaction and wallet RPCs. It's set from `-maxtxfee`.

~listed in the global help text in init.cpp, but is only set in `WalletInit::ParameterInteraction()`. If the wallet is disabled, then `-maxtxfee` is ignored and the default is used.~

~This behaviour has existed since the mempool was changed to limit acceptance based on `maxTxFee` in https://github.com/bitcoin/bitcoin/commit/fa331db68bcc68e4c93fb45aaa30f911b0ecfe1a.~

~Short-term fix is to move the `-maxtxfee` handling to `InitParameterInteraction()` in init.cpp.~
EDIT: `maxTxFee` initiation bug fixed in #15357 

I don't think we should share this setting between the node and wallet.
{
    RPCServer::OnStarted(&OnRPCStarted);
    RPCServer::OnStopped(&OnRPCStopped);
    if (!InitHTTPServer())
        return false;
    StartRPC();
    if (!StartHTTPRPC())
        return false;
    if (gArgs.GetBoolArg("-rest", DEFAULT_REST_ENABLE)) StartREST();
    StartHTTPServer();
    return true;
}
void InitParameterInteraction()
{
    
    
    if (gArgs.IsArgSet("-bind")) {
        if (gArgs.SoftSetBoolArg("-listen", true))
            LogPrintf("%s: parameter interaction: -bind set -> setting -listen=1\n", __func__);
    }
    if (gArgs.IsArgSet("-whitebind")) {
        if (gArgs.SoftSetBoolArg("-listen", true))
            LogPrintf("%s: parameter interaction: -whitebind set -> setting -listen=1\n", __func__);
    }
    if (gArgs.IsArgSet("-connect")) {
        
        if (gArgs.SoftSetBoolArg("-dnsseed", false))
            LogPrintf("%s: parameter interaction: -connect set -> setting -dnsseed=0\n", __func__);
        if (gArgs.SoftSetBoolArg("-listen", false))
            LogPrintf("%s: parameter interaction: -connect set -> setting -listen=0\n", __func__);