facedetector: Fix memory leak
facedetector: Fix memory leak

Change-Id: Ib9abe62a0962d883ea334e90705bcb4f3ac00b4b

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