Correctly ignore Marionette tests

We default to marionette these days. Handle that a
little more cleanly.

Author: shs96c

java/client/test/org/openqa/selenium/testing/drivers/TestIgnorance.java

@@ -181,7 +181,8 @@ private void addIgnoresForBrowser(Browser browser, IgnoreComparator comparator)
         break;
 
       case ff:
-        if (Boolean.getBoolean("webdriver.firefox.marionette")) {
+        if (System.getProperty("webdriver.firefox.marionette") == null ||
+            Boolean.getBoolean("webdriver.firefox.marionette")) {
           comparator.addDriver(MARIONETTE);
         } else {
           comparator.addDriver(FIREFOX);