Move gateway_mode to DEFAULT section.

Change-Id: I350ba1c79b2547ec04804a266dffc4d4c5a30fce
Closes-Bug:#1635215

src/vnsw/agent/contrail-vrouter-agent.conf

@@ -72,6 +72,9 @@ log_local=1
 # xmpp_server_key=/etc/contrail/ssl/private/server-privkey.pem
 # xmpp_ca_cert=/etc/contrail/ssl/certs/ca-cert.pem
 
+# Gateway mode : can be server/ vcpe (default is none)
+# gateway_mode=
+
 [DISCOVERY]
 #If DEFAULT.collectors and/or CONTROL-NODE and/or DNS is not specified this
 #section is mandatory. Else this section is optional
@@ -180,9 +183,6 @@ log_local=1
 # (like metadata...)
 #compute_node_address = 10.204.216.28
 
-# Gateway mode : can be server/ vcpe (default is none)
-# gateway_mode=
-
 # We can have multiple gateway sections with different indices in the
 # following format
 [GATEWAY-0]