This patch removes a task which adds an entry to /etc/hosts for
the hostname / 127.0.1.1.
Some services, such as rabbitmq, require that the ip address they
are configured to listen on resolves to a hostname with the same
ip. Before this patch there were two /etc/hosts entries for the
hostname of each host, 127.0.1.1 and the mgmt network address.
This patch ensures that the /etc/hosts file is unambiguous and
always resolves the hostname to the mgmt network ip address.
Change-Id: I5c9bf4cd0a3a416447f6f1797df4657402a64382
a71523f7c3