Configure ZooKeeper connection to ONOS/RAMCloud

- ZooKeeper server list specified by zookeeper.hosts (onos_node.conf)
  will be used as ZooKeeper fallback connection list for
  ONOS, RAMCloud. (ONOS-1756)

Change-Id: Iaef6bee82a28f3181f3fc681707666033f8d746f
diff --git a/conf/template/zoo.cfg.template b/conf/template/zoo.cfg.template
index 39dc329..69bd3c0 100644
--- a/conf/template/zoo.cfg.template
+++ b/conf/template/zoo.cfg.template
@@ -11,7 +11,7 @@
 # example sakes.
 dataDir=__DATADIR__
 # the port at which the clients will connect
-clientPort=2181
+clientPort=__CLIENTPORT__
 #
 # specify all servers in the Zookeeper ensemble
 #server.1=onosgui1:2888:3888