poky.conf: Update to post release versioning

(From meta-yocto rev: 2c574e299d247f3db0dcea513dc9ea818c488e72)

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

meta-poky/conf/distro/poky.conf

@@ -1,6 +1,6 @@
 DISTRO = "poky"
 DISTRO_NAME = "Poky (Yocto Project Reference Distro)"
-DISTRO_VERSION = "4.3"
+DISTRO_VERSION = "4.3+snapshot-${METADATA_REVISION}"
 DISTRO_CODENAME = "nanbield"
 SDK_VENDOR = "-pokysdk"
 SDK_VERSION = "${@d.getVar('DISTRO_VERSION').replace('snapshot-${METADATA_REVISION}', 'snapshot')}"