kmsbasertpendpoint: improve getting lock for properties getter/setter
kmsbasertpendpoint: improve getting lock for properties getter/setter

Change-Id: Ied08a76c007211d8f1163e92b81f614df08bf7af

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