ndns: Update for ndn-cxx 0.5.1

Change-Id: I8e9b1f80395bf8618a9f919c2b0d9b3ba546e3d3
diff --git a/ndns/Makefile b/ndns/Makefile
index 0ea3af3..f19cfc7 100644
--- a/ndns/Makefile
+++ b/ndns/Makefile
@@ -11,6 +11,6 @@
 VERSION=0.0.6-gdc2df
 
 # PPA version
-PPA_VERSION=1
+PPA_VERSION=2
 
 include ../packaging.mk