Work around problem with concurrent-output when in a non-unicode locale by avoiding use of it in such a locale.

Instead -J will behave as if it was built without concurrent-output support
in this situation. Ie, it will be mostly quiet, except when there's an
error.

Note that it's not a problem for a filename to contain invalid utf-8 when
in a utf-8 locale. That is handled ok by concurrent-output. It's only
displaying unicode characters in a non-unicode locale that doesn't work.

Messages.hs

@@ -212,7 +212,7 @@ commandProgressDisabled = withOutputType $ \t -> return $ case t of
 	QuietOutput -> True
 	JSONOutput -> True
 	NormalOutput -> False
-	ConcurrentOutput _ -> True
+	ConcurrentOutput {} -> True
 
 {- Use to show a message that is displayed implicitly, and so might be
  - disabled when running a certian command that needs more control over its