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.
uint32_t getLogCategories() override { return g_logger->GetCategoryMask(); }
    bool baseInitialize() override
    {
        return AppInitBasicSetup() && AppInitParameterInteraction() && AppInitSanityChecks() &&
               AppInitLockDataDirectory();
    }
    bool appInitMain() override { return AppInitMain(); }
    void appShutdown() override
    {
        Interrupt();
        Shutdown();
    }
    void startShutdown() override { StartShutdown(); }
    bool shutdownRequested() override { return ShutdownRequested(); }
    void mapPort(bool use_upnp) override
    {
        if (use_upnp) {
            StartMapPort();
        } else {
            InterruptMapPort();
            StopMapPort();
        }
    }
    void setupServerArgs() override { return SetupServerArgs(); }
    bool getProxy(Network net, proxyType& proxy_info) override { return GetProxy(net, proxy_info); }
    size_t getNodeCount(CConnman::NumConnections flags) override
    {
        return g_connman ? g_connman->GetNodeCount(flags) : 0;
    }
    bool getNodesStats(NodesStats& stats) override