dist/ami: run nodetool status on each login
dist/ami: run nodetool status on each login

Running nodetool status on each login to Scylla AMI helps in three ways:
- give the user a quick view of the node and cluster status beyond the current "scylla is active"
- hint to the user about the nodetool and how to use it
- move the first, slow, run of nodetool to the login phase, making the second interactive run much faster

on the down side, it does slow the login in a few sec

Signed-off-by: Tzach Livyatan <434a324262fc65c9776045522d30d755c828b1aa@scylladb.com>
[ penberg: fix formatting ]
Message-Id: <20170330081711.22038-1-434a324262fc65c9776045522d30d755c828b1aa@scylladb.com>

avikivity/scylla,scylladb/scylla,scylladb/scylla,scylladb/scylla,duarten/scylla,duarten/scylla,avikivity/scylla,duarten/scylla,scylladb/scylla,avikivity/scylla