Test if other RPC server is alive and act appropriately.

Ping the server, and if a reply is received, do nothing. If no reply
is received, prompt to replace the server.

Change-Id: Ic0596356951cae363dfac33cc3eddb38aa87be59
Merge topic 'rpc-clobber' into master

a4e535fe Test if other RPC server is alive and act appropriately.