collapse_todo_ids() uses `git rev-parse --short=7' to abbreviate
commit ids before showing them to the user in a text editor. Let's
drop argument from --short to the configured value instead (still
defaulting to 7).
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Eric Sunshine <sunshine@sunshineco.com> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>