TMSS-2824: added default for older schemas

SAS/TMSS/backend/src/tmss/tmssapp/adapters/parset.py

@@ -495,7 +495,7 @@ def _convert_to_parset_dict_for_observationcontrol_schema(subtask: models.Subtas
         parset[prefix+"ObservationControl.OnlineControl.CorrAppl.CorrProc._hostname"] = "cbmmaster"
         parset[prefix+"ObservationControl.OnlineControl.CorrAppl.CorrProc._nodes"] = []
         parset[prefix+"ObservationControl.OnlineControl.CorrAppl.CorrProc._startstopType"] = "bgl"  # note: this is three correlators ago, and hopefully we get rid of it in LOFAR 2.0 ;)
-        parset[prefix+"ObservationControl.OnlineControl.CorrAppl.CorrProc.workingdir"] = f"/opt/lofar-versions/{spec['COBALT']['release']}/bin"
+        parset[prefix+"ObservationControl.OnlineControl.CorrAppl.CorrProc.workingdir"] = f"/opt/lofar-versions/{spec['COBALT'].get('release', 'current')}/bin"
         parset[prefix+"ObservationControl.OnlineControl.CorrAppl._hostname"] = "cbmmaster"
         parset[prefix+"ObservationControl.OnlineControl.CorrAppl.extraInfo"] = '["PIC","Cobalt"]'
         parset[prefix+"ObservationControl.OnlineControl.CorrAppl.procesOrder"] = []    # note: typo is correct ;)