PostReplicatedChange called for fast array item even when no values change

Unless a property is set to REPNOTIFY_Always, we compare the property's received value to the current value on the client before calling the OnRep function.
However, when determining if a fast array item has changed, all that is checked is the ReplicationKey of the item, which is incremented when MarkItemDirty is called. Even if the properties haven't changed, the client still receives the item as a changed element, and so PostReplicatedChange is still called for the item (as well as the fast array's repnotify function if one is set).

Call MarkItemDirty on a replicated fast array item without changing the value of any of the item's properties.