webadmin: tiny fix for make template dialog's focus traversal

The tab index of 'Quota' combobox is wrong, resulting in wrong focus
traversal order.

This patch fix it by giving the 'Quota' combobox the right tab index so
that it will be focused right after 'Host Cluster' combobox.

Change-Id: If568deb65aaa03a1a422bd6cf7d41dface29ba5e
Bug-Url: https://bugzilla.redhat.com/873133
Signed-off-by: Arik Hadas <ahadas@redhat.com>