git-filter-repo.txt: fix extraneous space

Signed-off-by: Elijah Newren <newren@gmail.com>

Documentation/git-filter-repo.txt

@@ -992,7 +992,7 @@ backward compatibility caveats mentioned previously):
          `tagger_date`, `message`
   * Commit: `branch`, `original_id`, `author_name`, `author_email`,
             `author_date`, `committer_name`, `committer_email`,
-            `committer_date `, `message`, `file_changes` (list of
+            `committer_date`, `message`, `file_changes` (list of
             FileChange objects, each containing a `type`, `filename`,
             `mode`, and `blob_id`), `parents` (list of hashes or integer
             marks)