Remove link to Java bug since it is not any more

spring-kafka-test/src/main/java/org/springframework/kafka/test/rule/Log4jLevelAdjuster.java

@@ -93,7 +93,6 @@ public class Log4jLevelAdjuster implements MethodRule {
 					logger.debug("++++++++++++++++++++++++++++ "
 							+ "Restoring log level setting for: " + Arrays.asList(classes) + " and "
 							+ Arrays.asList(categories) + " for test " + method.getName());
-					// raw Class type used to avoid https://bugs.java.com/view_bug.do?bug_id=6682380
 					for (Class<?> cls : classes) {
 						LogManager.getLogger(cls).setLevel(oldLevels.get(cls));
 					}