Fix URLClassLoaderTest#test_addURLLjava_net_URL

OpenJdk implementation of URLClassLoader discards null values.

Change-Id: Ie2c8ec9f66efb28b8d8a5b77508e5d02a81fc919
diff --git a/luni/src/test/java/libcore/java/net/OldURLClassLoaderTest.java b/luni/src/test/java/libcore/java/net/OldURLClassLoaderTest.java
index c076f1d..2aea4ef 100644
--- a/luni/src/test/java/libcore/java/net/OldURLClassLoaderTest.java
+++ b/luni/src/test/java/libcore/java/net/OldURLClassLoaderTest.java
@@ -117,7 +117,7 @@
 
         URL [] urls = {new URL("http://foo.com/foo"),
                        new URL("jar:file://foo.jar!/foo.c"),
-                       new URL("ftp://foo1/foo2/foo.c"), null};
+                       new URL("ftp://foo1/foo2/foo.c")};
 
         TestURLClassLoader tucl = new TestURLClassLoader(u);