Remove workaround for showing the TBB's menu bar
Originally created by @anonym on #8028 (Redmine)
We want to revert commit 63ed6bb if the TBB starts showing the menu bar by default again, which seems likely: https://lists.torproject.org/pipermail/tor-qa/2014-October/000478.html
Feature Branch: feature/8028-remove-unsafe-browser-test-menu-workaround