added setSpec to dto object for keeping the setSpec after updating the bundlesSource

src/main/java/org/gesis/dda/wizard/service/BundlesSourceService.java

@@ -66,6 +66,8 @@ public class BundlesSourceService {
             
             XsltOaiPmhDto updatedDto = new XsltOaiPmhDto(
                     originalDto.getOaiPmhEndpoint(),
+                    // added setSpec for keeping it after first harvest
+                    originalDto.getSetSpec(),
                     originalDto.getMetadataPrefix2XsltMap(),
                     nextIncrementalHarvestingStartInstant,
                     null);