Bug 1567648 [wpt PR 17930] - Update wpt metadata, a=testonly

wpt-pr: 17930
wpt-type: metadata

testing/web-platform/meta/webrtc/idlharness.https.window.js.ini

@@ -578,3 +578,6 @@
   [RTCError interface: existence and properties of interface object]
     expected: FAIL
 
+  [idl_test setup]
+    expected: FAIL
+