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.
LogPrintf("Setting version bits activation parameters for %s to start=%ld, timeout=%ld\n", vDeploymentParams[0], nStartTime, nTimeout);
                break;
            }
        }
        if (!found) {
            throw std::runtime_error(strprintf("Invalid deployment (%s)", vDeploymentParams[0]));
        }
    }
}
static std::unique_ptr<const CChainParams> globalChainParams;
const CChainParams &Params() {
    assert(globalChainParams);
    return *globalChainParams;
}
std::unique_ptr<const CChainParams> CreateChainParams(const std::string& chain)
{
    if (chain == CBaseChainParams::MAIN)
        return std::unique_ptr<CChainParams>(new CMainParams());
    else if (chain == CBaseChainParams::TESTNET)
        return std::unique_ptr<CChainParams>(new CTestNetParams());
    else if (chain == CBaseChainParams::REGTEST)
        return std::unique_ptr<CChainParams>(new CRegTestParams(gArgs));
    throw std::runtime_error(strprintf("%s: Unknown chain %s.", __func__, chain));
}
void SelectParams(const std::string& network)
{
    SelectBaseParams(network);
    globalChainParams = CreateChainParams(network);
}