Prepare for release 3.6.3

git-svn-id: https://svn.r-project.org/R/branches/R-3-6-branch@77875 00db46b3-68df-0310-9c12-caf00c1e9a41
diff --git a/VERSION b/VERSION
index 042c889..4a788a0 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-3.6.3 RC
+3.6.3