kmsbasertpendpoint: improve update_sdp_media
kmsbasertpendpoint: improve update_sdp_media

Change-Id: Icab43c813f679163d980298e7eecdd6c3c16dd14

TribeMedia/kms-core,TribeMedia/kms-core,shelsonjava/kms-core,ESTOS/kms-core,shelsonjava/kms-core,Kurento/kms-core,ESTOS/kms-core,Kurento/kms-core,Kurento/kms-core,Kurento/kms-core,shelsonjava/kms-core,TribeMedia/kms-core,ESTOS/kms-core,shelsonjava/kms-core,ESTOS/kms-core,TribeMedia/kms-core