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.
int currentConfirmationTarget = nTxConfirmTarget;
                if (coinControl && coinControl->nConfirmTarget > 0)
                    currentConfirmationTarget = coinControl->nConfirmTarget;
                
                if (fSendFreeTransactions && nBytes <= MAX_FREE_TRANSACTION_CREATE_SIZE)
                {
                    
                    double dPriorityNeeded = mempool.estimateSmartPriority(currentConfirmationTarget);
                    
                    if (dPriority >= dPriorityNeeded && AllowFree(dPriority))
                        break;
                }
                CAmount nFeeNeeded = GetMinimumFee(nBytes, currentConfirmationTarget, mempool);
                if (coinControl && nFeeNeeded > 0 && coinControl->nMinimumTotalFee > nFeeNeeded) {
                    nFeeNeeded = coinControl->nMinimumTotalFee;
                }
                if (coinControl && coinControl->fOverrideFeeRate)
                    nFeeNeeded = coinControl->nFeeRate.GetFee(nBytes);
                
                
                if (nFeeNeeded < ::minRelayTxFee.GetFee(nBytes))
                {
                    strFailReason = _("Transaction too large for fee policy");
                    return false;
                }
                if (nFeeRet >= nFeeNeeded) {