Bug 1318724 - Disable unstable WebDriver navigation test on a CLOSED TREE, a=testonly

MozReview-Commit-ID: 8IWeUArjtWY

testing/web-platform/meta/webdriver/navigation.py.ini

@@ -1,5 +1,7 @@
 [navigation.py]
   type: wdspec
+  disabled:
+    if (os == "linux") and (bits == 64) and debug: https://bugzilla.mozilla.org/show_bug.cgi?id=1318724
   [navigation.py::test_get_current_url_no_browsing_context]
     expected: ERROR