basehub: Avoid race conditions with concurrent calls to unhandle_port
basehub: Avoid race conditions with concurrent calls to unhandle_port

Change-Id: I790d525e3daa63438bfbff7820c2de9203ad8139

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