lp1713164 copy editor saving without call number

lp1713164 copy editor saving without call number
In the volume / copy editor if the user adds a copy without entering a
call number they are still able to save. There is no indication that
the call number is missing. The save doesn't go through in this case.
The task is to fix this bug.

Signed-off-by: Mike Risher <mrisher@catalyte.io>
Changes to be committed:
	modified:   Open-ILS/web/js/ui/default/staff/cat/volcopy/app.js