kmshttpendpoint: Fix memory leak managing caps
kmshttpendpoint: Fix memory leak managing caps

Change-Id: Ie20eabff58153eed3b3b01bb7b63ad521ba5e746

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