fix #47: XOriginTrimmingPolicy pref

lib/study.js

@@ -20,7 +20,7 @@ const studyConfig = {
     'noThirdPartyCookies': () => feature.studyPref('network.cookie.cookieBehavior', 1),
     'thirdPartyCookiesOnlyFromVisited': () => feature.studyPref('network.cookie.cookieBehavior', 3),
     'trackingProtection': () => feature.studyPref('privacy.trackingprotection.enabled', true),
-    'originOnlyRefererToThirdParties': () => feature.studyPref('network.http.referer.trimmingPolicy', 2),
+    'originOnlyRefererToThirdParties': () => feature.studyPref('network.http.referer.XOriginTrimmingPolicy', 2),
     'resistFingerprinting': () => feature.studyPref('privacy.resistFingerprinting', true)
   }
 };