pointerdetector: Fix problem when get an empty windows layout
pointerdetector: Fix problem when get an empty windows layout

Change-Id: I196c7d8c413fa1da0937b8676e7b3c3748b2e516

Kurento/kms-elements,TribeMedia/kms-elements,shelsonjava/kms-elements,Kurento/kms-elements,shelsonjava/kms-elements,Kurento/kms-elements,shelsonjava/kms-elements,TribeMedia/kms-elements,TribeMedia/kms-elements