Update postinst file to follow v2 security elements

Change-Id: I17e11e05043ba864052419604096e72a6238ec9c
diff --git a/ndn-tools/Makefile b/ndn-tools/Makefile
index 6fab05e..bba083f 100644
--- a/ndn-tools/Makefile
+++ b/ndn-tools/Makefile
@@ -11,6 +11,6 @@
 VERSION=0.5-14-gcc2c717b
 
 # PPA version
-PPA_VERSION=1
+PPA_VERSION=2
 
 include ../packaging.mk