Merge pull request #229 from wazo-platform/WAZO-3532-use-main-proxy-ip

Pull request for WAZO-3532-use-main-proxy-ip

digium: raise exception if no line is configured
why: we want to remove usage of raw_config['ip'] key in order to
deprecate this key. Moreover, a device without line doesn't make sense.
note: autoprov have one sip_line
yealink: use proxy_ip for action_uri_limit_ip
why:

we want to remove usage of raw_config['ip'] key in order to deprecate
this key.
IP is the provisioning server, and action_uri_limit_ip need to have
the PBX server.

note: taking the last line proxy_ip is only for convenience and have the
same issue than taking the first one

Reviewed-by: Alexandre Fournier