Documentation/git-clean.txt: don't mention deletion of .git/modules/*
Documentation/git-clean.txt: don't mention deletion of .git/modules/*

The latter half of this sentence, the removal of the submodules, was
never done with (or without) double -f back when it was written, and
we still do not do so.

Signed-off-by: Matt McCutchen <1fa2ef4755a9226cb9a0a4840bd89b158ac71391@mattmccutchen.net>
Signed-off-by: Junio C Hamano <a6723cc3f76163bf7adb636a73ac3b0ceb3e6b9b@pobox.com>

destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git