Bug 1488825 - Enable ExtensionStorageIDB backend on all channels. r=aswan

This patch enables the WebExtensions "browser.storage.local" IndexedDB backend
on non-Nightly channels.

Differential Revision: https://phabricator.services.mozilla.com/D16717

--HG--
extra : moz-landing-system : lando

modules/libpref/init/all.js

@@ -5124,11 +5124,7 @@ pref("extensions.webextensions.userScripts.enabled", false);
 pref("extensions.webextensions.background-delayed-startup", false);
 
 // Whether or not the installed extensions should be migrated to the storage.local IndexedDB backend.
-#ifdef NIGHTLY_BUILD
 pref("extensions.webextensions.ExtensionStorageIDB.enabled", true);
-#else
-pref("extensions.webextensions.ExtensionStorageIDB.enabled", false);
-#endif
 
 // if enabled, store execution times for API calls
 pref("extensions.webextensions.enablePerformanceCounters", true);