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.
{
    this->intro = _intro;
}
void FreespaceChecker::check()
{
    QString dataDirStr = intro->getPathToCheck();
    fs::path dataDir = GUIUtil::qstringToBoostPath(dataDirStr);
    uint64_t freeBytesAvailable = 0;
    int replyStatus = ST_OK;
    QString replyMessage = tr("A new data directory will be created.");
    
    fs::path parentDir = dataDir;
    fs::path parentDirOld = fs::path();
    while(parentDir.has_parent_path() && !fs::exists(parentDir))
    {
        parentDir = parentDir.parent_path();
        
        if (parentDirOld == parentDir)
            break;
        parentDirOld = parentDir;
    }