fix errors not being reported using http proxies

ext/bg.js

@@ -700,16 +700,9 @@ browser.webRequest.onErrorOccurred.addListener(
 		
 		if(global_ws === null){ return; }
 		
-		var pending_req = webreq_completed.get(page.requestId);
-
-		if(
-			// we're not watching that req
-			!pending_req ||
-			// some bullshit happened
-			pending_req.success === false
-		){
+		if(!web_response_whitelist.includes(page.type)){
 			
-			webreq_completed.delete(details.requestId);
+			webreq_completed.delete(page.requestId);
 			return;
 		}