Bug 1669488 - Unskip test xpinstall/browser_localfile2.js for fission, r=extension-reviewers,mixedpuppy,smaug

Differential Revision: https://phabricator.services.mozilla.com/D92639

toolkit/mozapps/extensions/test/xpinstall/browser.ini

@@ -69,7 +69,6 @@ skip-if = true # Bug 1449788
 [browser_installchrome.js]
 [browser_localfile.js]
 [browser_localfile2.js]
-skip-if = fission
 [browser_localfile3.js]
 [browser_localfile4.js]
 [browser_localfile4_postDownload.js]