Fix ProcFamilyUsage::operator+=() for total_proportional_set_size_available #4971
Fix ProcFamilyUsage::operator+=() for total_proportional_set_size_available #4971

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