message: Add self to prefetchSrc
  Fixes
diff: @@ -71,6 +71,7 @@ module.exports = function csp(env) {
  'https://platform.twitter.com/',
  'https://opencollective.com',
  ],
  + prefetchSrc: [SELF],
  objectSrc: SELF,
  // Web app manifest
  manifestSrc: SELF,
  