Hob was hanging when the user tried a rebuild a new image, because
of sanity checks. It should not re-run sanity checks.
[YOCTO #3829]
(Bitbake rev: f7ff550f53cf3e5b166940db83f27ec733f3ef72)
Signed-off-by: Cristiana Voicu <cristiana.voicu@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>