update ndnsec commands

Change-Id: Ib802fd40d53e0405b9707e76dec4f2a92f9affc5
diff --git a/minindn/apps/nfd.py b/minindn/apps/nfd.py
index 90a36b8..4b410b9 100644
--- a/minindn/apps/nfd.py
+++ b/minindn/apps/nfd.py
@@ -68,7 +68,7 @@
 
         if not Minindn.ndnSecurityDisabled:
             # Generate key and install cert for /localhost/operator to be used by NFD
-            node.cmd('ndnsec-keygen /localhost/operator | ndnsec-install-cert -')
+            node.cmd('ndnsec-key-gen /localhost/operator | ndnsec-cert-install -')
 
     def start(self):
         Application.start(self, 'nfd --config {}'.format(self.confFile), logfile=self.logFile)