upgrade scalachess to fix threefold repetition detection

ornicar · ornicar · commit e8f86b92728c · 2016-01-23T18:02:38.000+07:00
diff --git a/modules/chess b/modules/chess
@@ -1 +1 @@
-Subproject commit f86b5f235cd0f4c9a21dd1d7e7d84ab6da019d45
+Subproject commit a9f654ef8ddda281244bbf5b9725c61b9aa5a2b4
