core: better glance template description when importing

Change-Id: Ic753add97f59cc15c6521fb51ef762c5519c59fb
Bug-Url: https://bugzilla.redhat.com/1053544
Signed-off-by: Oved Ourfali <oourfali@redhat.com>
(cherry picked from commit 2781e93ab6572d140da2983b6ca97b1f7e6ac27d)