fix some mixed space+tab indentation

This fixes all instances of " \t" in the code base. Most common case
seems to be after a "where" line; probably vim copied the two space layout
of that line.

Done as a background task while listening to episode 2 of the Type Theory
podcast.

Remote/External.hs

@@ -169,7 +169,7 @@ handleRequest' lck external req mp responsehandler
 		go
 	| otherwise = go
   where
-  	go = do
+	go = do
 		sendMessage lck external req
 		loop
 	loop = receiveMessage lck external responsehandler