Launch NLSR with explicit configuration file

Change-Id: Icacb1b4f320a4aa7394f58611ba424924a4ae0c0
refs: #3039

ndn/nlsr.py

@@ -40,7 +40,7 @@ class Nlsr(NdnApplication):
         node.cmd("sudo sed -i 's|prefix .*netlab|prefix /ndn/edu/%s|g' %s" % (node.name, self.confFile))
 
     def start(self):
-        NdnApplication.start(self, "nlsr -d")
+        NdnApplication.start(self, "nlsr -d -f {} &".format(self.confFile))
 
 class NlsrConfigGenerator: