Add blank for license header check

tests/test-sessions/test-hash-sessions/src/test/java/org/eclipse/jetty/server/session/IdleSessionTest.java

@@ -15,6 +15,7 @@
 //  You may elect to redistribute this code under either of these licenses.
 //  ========================================================================
 //
+
 package org.eclipse.jetty.server.session;
 
 import static org.junit.Assert.assertEquals;