Need add python3-git to buildtools-tarball for the py3 build, and the
dependencies chain is:
python3-git -> python3-gitdb
(From OE-Core rev: b13babf07d77bcbed21c24761e2f4ada9ba85507)
Signed-off-by: Robert Yang <liezhi.yang@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>