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.

Annex/Transfer.hs

@@ -69,7 +69,7 @@ runTransfer' ignorelock t file shouldretry a = do
 			return False
 		else do
 			ok <- retry info metervar $
-		 		bracketIO (return fd) (cleanup tfile) (const $ a meter)
+				bracketIO (return fd) (cleanup tfile) (const $ a meter)
 			unless ok $ recordFailedTransfer t info
 			return ok
   where