Add openldap-compat
As reported by Maarten Litmaath: ATLAS reported some issues because openldap-compat is needed by GFAL but is not found on Grid sites, https://twiki.cern.ch/twiki/bin/view/LCG/WLCGOpsMeetingWeek240311#Monday
As reported by Maarten Litmaath: ATLAS reported some issues because openldap-compat is needed by GFAL but is not found on Grid sites, https://twiki.cern.ch/twiki/bin/view/LCG/WLCGOpsMeetingWeek240311#Monday