Upadte lib to HEAD

This fixes build failure under CCS 5.5.

diff --git a/rpp-lib b/rpp-lib
index f6138bc6b104c52db50971c13049ed7b5eaf66d3..ca54af8b73a6d9ebdc08121d11bb8dd77fad7516 160000 (submodule)
--- a/rpp-lib
+++ b/rpp-lib
@@ -1 +1 @@
-Subproject commit f6138bc6b104c52db50971c13049ed7b5eaf66d3
+Subproject commit ca54af8b73a6d9ebdc08121d11bb8dd77fad7516