Update BUCK version to match Gerrit master

Change-Id: Ib4e65889ff625fd4f344f4797246e47aa9d6bbc4
diff --git a/buckversion b/buckversion
index 9c09744..46408a5 100644
--- a/buckversion
+++ b/buckversion
@@ -1 +1 @@
-79d36de9f5284f6e833cca81867d6088a25685fb
+8204fddf60b25a3c2090f3ef0742fca5d466d562