Since we cannot stash dirty submodules, there is no use in requiring
them to be clean (or stash them when they are not).
This brings the built-in rebase in line with the previous, scripted
version, which also did not care about dirty submodules (but it was
admittedly not very easy to figure that out).
This fixes https://github.com/git-for-windows/git/issues/1820
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>