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.
#include <chainparams.h>
#include <init.h>
#include <interfaces/chain.h>
#include <net.h>
#include <scheduler.h>
#include <outputtype.h>
#include <util/system.h>
#include <util/moneystr.h>
#include <validation.h>
#include <walletinitinterface.h>
#include <wallet/rpcwallet.h>
#include <wallet/wallet.h>
#include <wallet/walletutil.h>
class WalletInit : public WalletInitInterface {