add final keyword

Author: vladak

opengrok-web/src/test/java/org/opengrok/web/PageConfigTest.java

@@ -683,7 +683,7 @@ void testIsNotModifiedNotModified() {
         DummyHttpServletRequest req = mock(DummyHttpServletRequest.class);
         when(req.getPathInfo()).thenReturn("/");
         PageConfig cfg = PageConfig.get(req);
-        String etag = cfg.getEtag();
+        final String etag = cfg.getEtag();
         when(req.getHeader(HttpHeaders.IF_NONE_MATCH)).thenReturn(etag);
         HttpServletResponse resp = mock(HttpServletResponse.class);
         assertTrue(cfg.isNotModified(req, resp));