[TIZEN] Add gz compression for the source archive

This permits to avoid a gbs export error on Tizen official OBS

BUG=XWALK-3222
Signed-off-by: Baptiste DURAND <baptiste.durand@open.eurogiciel.org>
This isn't enough, see how this tar(1) is invoked at the end: you're not passing --gzip to it so the new archive being created there is not compressed.