Fix bin/repository importing for CLOSEABLE flag
Summary: After adding the CLOSEABLE flag, bin/repository importing reports CLOSEABLE commits with no information. Just don't report these, for consistency with the old behavior. Adding flags to show them might be nice at some point if we run into issues where that output would be useful.
Test Plan: Ran bin/repositroy importing on a repository with CLOSEABLE commits.
Reviewers: btrahan
Reviewed By: btrahan
CC: aran
Differential Revision: https://secure.phabricator.com/D8024