self-hosted-image: Update poky revision to point at the 1.2 release branch

(From OE-Core rev: fd989e1bceef6df36619ba8944c8141abefd282e)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-core/images/self-hosted-image.bb

@@ -19,7 +19,7 @@ IMAGE_FSTYPES = "vmdk"
 
 inherit core-image
 
-SRCREV = "3ab5d73f0c49df9fefa2a46031d33436bbd7d"
+SRCREV = "3ab5d73f0c49df9fefa2a46031d33436bbd7d7d8"
 SRC_URI = "git://git.yoctoproject.org/poky;protocol=git"
 
 IMAGE_CMD_ext3_append () {