tck tests are done after ServletContext has already been initialized so we need to test this first to get some tck test passing... (#4514)

Signed-off-by: olivier lamy <oliver.lamy@gmail.com>

jetty-servlet/src/main/java/org/eclipse/jetty/servlet/ServletContextHandler.java

@@ -1299,15 +1299,15 @@ public class ServletContextHandler extends ContextHandler
         @Override
         public boolean setInitParameter(String name, String value)
         {
+            //since servlet spec 4.0
+            Objects.requireNonNull(name);
+
             if (!isStarting())
                 throw new IllegalStateException();
 
             if (!_enabled)
                 throw new UnsupportedOperationException();
 
-            //since servlet spec 4.0
-            Objects.requireNonNull(name);
-
             return super.setInitParameter(name, value);
         }