[libgames-support] scores: Do not copy delegate

[Michael Catanzaro <mcatanzaro src gnome org>]

commit 89b9a3d37be4912736d3b1e589a22451d69170b9
Author: Michael Catanzaro <mcatanzaro igalia com>
Date:   Sat Feb 13 23:59:25 2016 -0600

    scores: Do not copy delegate
    
    This really ought to be a hard error....

 games/scores/directory-importer.vala |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/games/scores/directory-importer.vala b/games/scores/directory-importer.vala
index c4450eb..b28f211 100644
--- a/games/scores/directory-importer.vala
+++ b/games/scores/directory-importer.vala
@@ -46,7 +46,7 @@ public class DirectoryImporter : Importer
 
     public DirectoryImporter.with_convert_func (CategoryConvertFunc? category_convert)
     {
-        this.category_convert = category_convert;
+        this.category_convert = (old_key) => { return category_convert (old_key); };
     }
 
     /* This scores format is mostly-compatible with the current format, the only