Add error message for unsupported URL scheme

Change-Id: I58f3af8331e1afd50ef2be27c4ba530498720022
Closes-Bug: 1438975

openstack_dashboard/dashboards/project/images/images/forms.py

@@ -200,6 +200,9 @@ class CreateImageForm(forms.SelfHandlingForm):
                             '%s for image.') % data['disk_format']
                 elif "Image name too long" in e.details:
                     msg = _('Unable to create new image: Image name too long.')
+                elif "not supported" in e.details:
+                    msg = _('Unable to create new image: URL scheme not '
+                            'supported.')
 
             exceptions.handle(request, msg)