P4 tools version bump

Change-Id: I39bfba21fb90334ca4cae05ce06c34ddeafd02ab
diff --git a/protocols/p4runtime/proto/BUCK b/protocols/p4runtime/proto/BUCK
index 8239990..a50c71f 100644
--- a/protocols/p4runtime/proto/BUCK
+++ b/protocols/p4runtime/proto/BUCK
@@ -5,7 +5,7 @@
 PROTOBUF_VER = '3.0.2'
 GRPC_VER = '1.3.0'
 
-PI_COMMIT = 'b7053f7ad32eb8cddab2ed1f4a7e1e6a30fc5e57'
+PI_COMMIT = '9fc50cd0a0187eb1346272524d4b8bafb51bb513'
 PI_BASEURL = 'https://github.com/p4lang/PI.git'
 
 # Wondering which .proto files to build? Check p4runtime's Makefile: