Removed "janky" snowflake state machine

The only place it was used was in window.onpageunload, and we have a
better way of determining if the proxy is active there (through the ui).

I also removed that code from the webextension since the proxy won't
stop running unless you close the browser and after testing it looks
like that code doesn't notify the user anyway.

proxy/init-badge.js

@@ -193,7 +193,7 @@ var debug, snowflake, config, broker, ui, log, dbg, init, update, silenceNotific
     if (
       !silenceNotifications &&
       snowflake !== null &&
-      Snowflake.MODE.WEBRTC_READY === snowflake.state
+      ui.active
     ) {
       return Snowflake.MESSAGE.CONFIRMATION;
     }