TORONTO — Finally, the Knicks face the defending champs. The first Knicks-Thunder matchup of the season is Wednesday at MSG — more than five months into the campaign — and not ideal circumstances for Mike Brown’s squad. The Knicks will be operating on a back-to-back after beating the Raptors 111-95 on Tuesday and flying from Toronto to New York. It’s a big test — and a potential Finals preview — but both Brown and Josh Hart agreed it won’t serve as an indictment on where the Knicks stand, win