SSDM-4761 OpenbisSync full-sync feature. fix for case when the timestamp file does not exist

SVN: 38075

datastore_server/source/java/ch/ethz/sis/openbis/generic/server/dss/plugins/sync/harvester/HarvesterMaintenanceTask.java

@@ -155,7 +155,7 @@ public class HarvesterMaintenanceTask<T extends DataSetInformation> implements I
                 loadCutOffTimeStamps(lastSyncTimestampFile);
 
                 Date cutOffTimestamp = lastIncSyncTimestamp;
-                boolean isFullSync = isTimeForFullSync(config);
+                boolean isFullSync = lastSyncTimestampFile.exists() == false || isTimeForFullSync(config);
                 if (isFullSync == true)
                 {
                     cutOffTimestamp = new Date(0L);