Update rpp-lib submodule

diff --git a/rpp-lib b/rpp-lib
index 5cdc272011e0d887d1297641a7f9bdcc6173b12d..df67e668b0bbfd7bb543ea62780753422411923c 160000 (submodule)
--- a/rpp-lib
+++ b/rpp-lib
@@ -1 +1 @@
-Subproject commit 5cdc272011e0d887d1297641a7f9bdcc6173b12d
+Subproject commit df67e668b0bbfd7bb543ea62780753422411923c