fix sonar warnings

commafeed-server/src/main/java/com/commafeed/backend/feed/FeedRefreshUpdater.java

@@ -114,6 +114,7 @@ public class FeedRefreshUpdater {
 			}
 		} catch (InterruptedException e) {
 			log.error("interrupted while waiting for lock for {} : {}", feed.getUrl(), e.getMessage(), e);
+			Thread.currentThread().interrupt();
 		} finally {
 			if (locked1) {
 				lock1.unlock();

commafeed-server/src/main/java/com/commafeed/backend/feed/FeedUtils.java

@@ -20,12 +20,14 @@ import com.commafeed.backend.feed.parser.TextDirectionDetector;
 import com.commafeed.backend.model.FeedSubscription;
 import com.commafeed.frontend.model.Entry;
 
+import lombok.experimental.UtilityClass;
 import lombok.extern.slf4j.Slf4j;
 
 /**
  * Utility methods related to feed handling
  * 
  */
+@UtilityClass
 @Slf4j
 public class FeedUtils {