Shutdown attempts to load config.js as an old style module

[Standard8]

I noticed a use of Cu.import here:

aboutsync/ext_bootstrap.js

Lines 175 to 178 in b4fd012

	const { Config } = Cu.import("chrome://aboutsync/content/config.js", {});
	Config.finalize();
	// And unload it, so changes will get picked up if we reload the addon.
	Cu.unload("chrome://aboutsync/content/config.js");

In the startup function, that gets imported as an ES module:

aboutsync/ext_bootstrap.js

Line 145 in b4fd012

const { Config } = ChromeUtils.importESModule("chrome://aboutsync/content/config.js");

So it looks wrong that it is being treated differently.

Additionally, since ES modules can't be unloaded, it may need to be handled slightly differently. I believe that one workaround has been to use something like ChromeUtils.importESModule("chrome://aboutsync/content/config.js?r=" + Math.rand());