CommitController: Don't turn of off automatic rearranging
In
a6b7c0c2a6 (GitCommitController: Also use dictionary lookup for untracked files),
we started using a dictionary when updating the index to avoid O(n^2) lookups
and make the code cleaner at the same time.
Before that change we temporarily stopped tracking the index, so that
the controller wasn't fired with hundreds of KVO notifications. in
a6b7c0c2a6,
we removed the re-tracked, but accidentally kept the untracking portion, which
meant that some index changes would not propagate to the controllers.