bloom: ignore renames when computing changed paths

The changed-path Bloom filters record an entry in the filter for every path that was changed. This includes every add and delete, regardless of whether a rename was detected. Detecting renames causes significant performance issues, but also will trigger downloading missing blobs in partial clone. The simple fix is to disable rename detection when computing a changed-path Bloom filter. This should already be disabled by default, but it is good to explicitly enforce the intended behavior. Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>