add more elastic logs

dmp-backend/elastic/src/main/java/eu/eudat/elastic/repository/ElasticRepository.java

@@ -30,6 +30,7 @@ public abstract class ElasticRepository<T extends ElasticEntity,C extends Criter
             }
         } catch (IOException e) {
             logger.warn("Unable to connect to Elastic Services");
+            logger.error(e.getMessage(), e);
             this.client = null;
         }
     }