sdp_agent: Fix compilation issue on xenial
sdp_agent: Fix compilation issue on xenial

Change-Id: I7a10ab2b518736458c4901c6adfcf26000a7c49a

Kurento/kms-core,ESTOS/kms-core,Kurento/kms-core,ESTOS/kms-core,ESTOS/kms-core,ESTOS/kms-core,Kurento/kms-core,Kurento/kms-core