OnRep_ReplicatedAnimMontage causes popping when montage ends

UAbilitySystemComponent::OnRep_ReplicatedAnimMontage doesn't handle some edge cases when stopping the montage when blending is involved. Namely, it's possible on a client (due to latency, etc.) that the local version of a montage ends before the replicated notification. When this happens, the replicated information will contain information for both changing the montage section back to 0 and ending the montage.

This is most noticeable when the starting pose of the montage is significantly different than the ending pose of the section played and the pose that's being blended to.

1. Download the attached zip file.
2. Extract this directly into QAGame.
3. Open up TestMap (should be located directly under Content).
4. Change number of players to 2, then PIE
5. In the server window, press 1 to trigger the montage.
6. Observe the montage playing in the client window.

Expected: The montage plays normally, and there's no visual popping.
Actual: The montage plays normally, but just before it finishes on the client it "pops" momentarily.