After update nodejs from system to 6.x in patch[1],
ubuntu xenial nodejs related files will be link to a loop:
/usr/local/bin/node -> /usr/bin/nodejs
/usr/bin/node -> /usr/bin/nodejs
/usr/bin/nodejs -> /etc/alternatives/nodejs
/etc/alternatives/nodejs -> /usr/bin/node
Also, in openstack-infra/system-config, the code we have for
etherpad node can't bringup one, we should remove the node
'Node-OS: xenial' that may misslead others
This patch is aimed to help etherpad node's system upgrade
to xenial.
[1] Ied9e5bd7ffa16f1832d3e1e26d0886de67f98f72
Change-Id: I6f7d50bed470916f7b150785ef68d34f336cb0ce