Fixes failing rpc_fundrawtransaction test on master due to botched backport D2673
Initially, it was thought that the entirety of the CoinControl block in GetMinimumFee was not needed since we're
not backporting the RBF and other fee-rated controls. However, this missed the case where this block was removed
from wallet.cpp and did not have a replacement:
if (coinControl && coinControl->fOverrideFeeRate) {
nFeeNeeded = coinControl->nFeeRate.GetFeeCeiling(nBytes);
}