install_helpers: add dependency libpcap-dev

refs #2519

Change-Id: I10feb52c1358cd31efe4b207e32d3c29365bbe80
diff --git a/install_helpers/install_ndncxx.py b/install_helpers/install_ndncxx.py
index d5d6fa0..150870c 100644
--- a/install_helpers/install_ndncxx.py
+++ b/install_helpers/install_ndncxx.py
@@ -1,7 +1,7 @@
 #!/usr/bin/python2
 import os
 
-# Install ndn-cpp-dev
+# Install ndn-cxx
 def run():
     print "\nINSTALLING ndn-cxx"
     print "**********************"