webadmin: refresh data on templates-disks sub-tab

Templates main-tab -> Disks sub-tab:
ensure storage domains data refresh.

Change-Id: Iea5004501dbdb1a3818e479633db5d6ba0249086
Bug-Url: https://bugzilla.redhat.com/972669
Signed-off-by: Daniel Erez <derez@redhat.com>