Fix double-delete in condor_advertise
Fix double-delete in condor_advertise

Would happen if you had multiple zero attribute classads in the file

htcondor/htcondor,htcondor/htcondor,htcondor/htcondor,htcondor/htcondor,htcondor/htcondor,htcondor/htcondor,htcondor/htcondor,htcondor/htcondor