Do not infer startup URLs in JUnitShell

Review at http://gwt-code-reviews.appspot.com/612801


git-svn-id: https://google-web-toolkit.googlecode.com/svn/trunk@8258 8db76d5a-ed1c-0410-87a9-c151d255dfc7
diff --git a/user/src/com/google/gwt/junit/JUnitShell.java b/user/src/com/google/gwt/junit/JUnitShell.java
index 2c2ff0f..b632d42 100644
--- a/user/src/com/google/gwt/junit/JUnitShell.java
+++ b/user/src/com/google/gwt/junit/JUnitShell.java
@@ -944,6 +944,11 @@
   }
 
   @Override
+  protected void inferStartupUrls() {
+    // do nothing -- JUnitShell isn't expected to have startup URLs
+  }
+
+  @Override
   protected ModuleDef loadModule(TreeLogger logger, String moduleName,
       boolean refresh) throws UnableToCompleteException {
     // Never refresh modules in JUnit.