falling back to the bundled permission was a bad idea. Admin would do.

git-svn-id: https://hudson.dev.java.net/svn/hudson/trunk/hudson/main@6425 71c3de6d-444a-0410-be80-ed276b4c234a

core/src/main/java/hudson/model/Hudson.java

@@ -2135,8 +2135,7 @@ public final class Hudson extends View implements ItemGroup<TopLevelItem>, Node,
      *      Define a custom {@link Permission} and check against ACL.
      */
     public static boolean isAdmin() {
-        return !getInstance().isUseSecurity()
-            || Hudson.getInstance().getACL().hasPermission(Permission.FULL_CONTROL);
+        return Hudson.getInstance().getACL().hasPermission(ADMINISTER);
     }
 
     /**