If one calls `fundrawtransaction`, the change address will be retrieved from the keypool, though, this key/address will always be returned to the pool, leading to the problem that the next `getnewaddress()` call will restult in the same key/address.

Either we remove the auto-change-address (users would need to call `getrawchangeaddress` first [current best practice anyway]) or we add a call to keep/mark a specific key/address as change (after one have sent the funded raw transaction).

Reported by @NicolasDorier on IRC.
std::reverse(vValue.begin(), vValue.end());
    vector<char> vfBest;
    CAmount nBest;
    ApproximateBestSubset(vValue, nTotalLower, nTargetValue, vfBest, nBest);
    if (nBest != nTargetValue && nTotalLower >= nTargetValue + MIN_CHANGE)
        ApproximateBestSubset(vValue, nTotalLower, nTargetValue + MIN_CHANGE, vfBest, nBest);
    
    
    if (coinLowestLarger.second.first &&
        ((nBest != nTargetValue && nBest < nTargetValue + MIN_CHANGE) || coinLowestLarger.first <= nBest))
    {
        setCoinsRet.insert(coinLowestLarger.second);
        nValueRet += coinLowestLarger.first;
    }
    else {
        for (unsigned int i = 0; i < vValue.size(); i++)
            if (vfBest[i])
            {
                setCoinsRet.insert(vValue[i].second);
                nValueRet += vValue[i].first;
            }
        LogPrint("selectcoins", "SelectCoins() best subset: ");
        for (unsigned int i = 0; i < vValue.size(); i++)
            if (vfBest[i])
                LogPrint("selectcoins", "%s ", FormatMoney(vValue[i].first));
        LogPrint("selectcoins", "total %s\n", FormatMoney(nBest));
    }
    return true;
}
bool CWallet::SelectCoins(const vector<COutput>& vAvailableCoins, const CAmount& nTargetValue, set<pair<const CWalletTx*,unsigned int> >& setCoinsRet, CAmount& nValueRet, const CCoinControl* coinControl) const