bufferinjector: Check if segment event is present before injecting a buffer
bufferinjector: Check if segment event is present before injecting a buffer

Change-Id: I70b2fd8c6b3f9e8b83b8d43ccc898ea56e3337de

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