fixup! Firefox preference overrides.

Bug 42647: Remove unused preference
browser.device-migration.help-menu.hidden.

browser/app/profile/001-base-profile.js

@@ -20,9 +20,6 @@ pref("browser.aboutwelcome.enabled", false);
 // Disable the Firefox View tab (tor-browser#41876)
 pref("browser.tabs.firefox-view", false, locked);
 
-// Disable 'Switching to a new device" help menu item (tor-browser#41774)
-pref("browser.device-migration.help-menu.hidden", true);
-
 #if MOZ_UPDATE_CHANNEL == release
 // tor-browser#42640: Disable Firefox Flame buttond due to unknown interactions with New Identity
 pref("browser.privatebrowsing.resetPBM.enabled", false, locked);