frontend: in some cases the display options are not taken from template

The problem was that first the options depending on the display
protocol has been copied from template to VM and then the display
type. It could happen, that you had a display protocol e.g. VLC
and than you have selected something which makes sense only for
SPICE, than this options have been ignored.

Fixed by moving the relevant options under the display protocol
setting.

Change-Id: I77a995eff3e800ba000cc3049eb1929d30ee91e8
Bug-Url: https://bugzilla.redhat.com/952712
Signed-off-by: Tomas Jelinek <tjelinek@redhat.com>