fix build with old version of Data.Set that lacks toDescList

Logs/MetaData.hs

@@ -24,6 +24,7 @@
  -}
 
 {-# OPTIONS_GHC -fno-warn-orphans #-}
+{-# LANGUAGE CPP #-}
 
 module Logs.MetaData (
 	getCurrentMetaData,
@@ -120,7 +121,11 @@ simplifyLog s = case sl of
 			else s
 	_ -> s
   where
+#if MIN_VERSION_containers(0,5,0)
 	sl = S.toDescList s
+#else
+	sl = reverse (S.toAscList s)
+#endif
 
 	go c _ [] = c
 	go c newer (l:ls)