webadmin: Change storage dialog styles to fit to size with French local

When using webadmin localized to French the storage dialog exceeded it's
size and an inner scroll bar appeared, styles were adjusted to make the
elements fit the size in French locale

Change-Id: Ia4b77224d4a9a4ab9f3da8428dbf743da48b53ac
Signed-off-by: Tal Nisan <tnisan@redhat.com>