pyshtables.py should be ignored by git as it is generated. If kept in
the repo, causes subsequent runs of sdk-update to fail.
[ YOCTO #10963 ]
(From OE-Core rev: 0ac1387bd12b5d023dea06ffe65d1fdcb050bcb4)
Signed-off-by: Andrea Galbusera <gizero@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>