Try to fix katana build

jechter · jechter · commit e743ead0761c · 2018-05-25T14:24:06.000+02:00
diff --git a/external/bdwgc b/external/bdwgc
@@ -1 +1 @@
-Subproject commit cee60fa2817b4b68cb7f864938c815ee24f11805
+Subproject commit 6f932c1b9af6d6ab9203131a4a14a961def5ee68
