httpendpoint: Remove elements from external thread
httpendpoint: Remove elements from external thread

Change-Id: I53e1e45f583ca5f7a33847a8d28ac2279c63a6a9

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