update systemd default parameter in NDNCERT and update ndncert-ca-server

Change-Id: I56d01b5125602ca54b9726225ca50e26630ddd39
diff --git a/systemd/ndncert-ca.service.in b/systemd/ndncert-ca.service.in
index 8ab77ac..5ac1a2b 100644
--- a/systemd/ndncert-ca.service.in
+++ b/systemd/ndncert-ca.service.in
@@ -3,7 +3,7 @@
 
 [Service]
 Environment=HOME=%S/ndncert-ca
-ExecStart=@BINDIR@/ndncert-ca-server -r
+ExecStart=@BINDIR@/ndncert-ca-server
 Restart=on-failure
 RestartPreventExitStatus=2
 User=ndn