facedetector: Fix memory leak
facedetector: Fix memory leak

Change-Id: Ib9abe62a0962d883ea334e90705bcb4f3ac00b4b

shelsonjava/kms-core,ESTOS/kms-core,TribeMedia/kms-core,shelsonjava/kms-core,Kurento/kms-core,KurentoLegacy/gst-kurento-plugins,TribeMedia/kms-core,TribeMedia/kms-core,KurentoLegacy/gst-kurento-plugins,shelsonjava/kms-core,ESTOS/kms-core,KurentoLegacy/gst-kurento-plugins,shelsonjava/kms-core,Kurento/kms-core,Kurento/kms-core,Kurento/kms-core,TribeMedia/kms-core,ESTOS/kms-core,ESTOS/kms-core,KurentoLegacy/gst-kurento-plugins