Using a Bitcoin-Qt v0.16.0 ([downloaded from bitcoin page](https://bitcoin.org/bin/bitcoin-core-0.16.0/bitcoin-0.16.0-osx.dmg)) in an macOS High Sierra 10.13.4 

When I start after a fresh install Bitcoin-Qt as a mainnet node and wallet, the wallet prompt that about 203gb is going to be used in my disk
![image](https://user-images.githubusercontent.com/20187136/39899688-ba820bfe-5493-11e8-87d9-460ed5716a02.png)

When I start the node and wallet as testnet, shows the same message about the 203gb disk usage
![image](https://user-images.githubusercontent.com/20187136/39899756-17b31214-5494-11e8-8a57-60e604e74afb.png)

It seems that the second time the message is wrong, due that the testnet database uses about 14gb.
#include <txmempool.h>
#include <ui_interface.h>
#include <util.h>
#include <validation.h>
#include <warnings.h>
#if defined(HAVE_CONFIG_H)
#include <config/bitcoin-config.h>
#endif
#include <atomic>
#include <boost/thread/thread.hpp>
#include <univalue.h>
class CWallet;
std::vector<std::shared_ptr<CWallet>> GetWallets();
namespace interfaces {
class Wallet;
namespace {
class NodeImpl : public Node
{
    bool parseParameters(int argc, const char* const argv[], std::string& error) override
    {
        return gArgs.ParseParameters(argc, argv, error);
    }
    bool readConfigFiles(std::string& error) override { return gArgs.ReadConfigFiles(error, true); }
    bool softSetArg(const std::string& arg, const std::string& value) override { return gArgs.SoftSetArg(arg, value); }
    bool softSetBoolArg(const std::string& arg, bool value) override { return gArgs.SoftSetBoolArg(arg, value); }
    void selectParams(const std::string& network) override { SelectParams(network); }
    std::string getNetwork() override { return Params().NetworkIDString(); }
    void initLogging() override { InitLogging(); }
    void initParameterInteraction() override { InitParameterInteraction(); }
    std::string getWarnings(const std::string& type) override { return GetWarnings(type); }