tests: use 'test_must_be_empty' instead of 'test_cmp <empty> <out>'

[git] / Documentation / RelNotes / 1.8.5.1.txt

Git v1.8.5.1 Release Notes
==========================

Fixes since v1.8.5
------------------

 * "git submodule init" copied "submodule.$name.update" settings from
   .gitmodules to .git/config without making sure if the suggested
   value was sensible.