MINOR: cli: Add possiblity to change agent config via CLI/socket

This change adds possibility to change agent-addr and agent-send directives
by CLI/socket. Now you can replace server's and their configuration without
reloading/restarting whole haproxy, so it's a step in no-reload/no-restart
direction.

Depends on #e9602af - agent-addr is implemented there.

Can be backported to 1.7.
1 file changed