core: Fix KeystoneAuthUrl example's description

The example of  KeystoneAuthUrl should include the version.

Change-Id: I387a15e66e8a45b52c9189253ac7b5898e9b2a75
Bug-Url: https://bugzilla.redhat.com/1075997
Signed-off-by: Moti Asayag <masayag@redhat.com>