Code review comment for lp://staging/~thedac/charm-helpers/lp1522130

I think this needs a fix for the HAproxy context, equivalent to the following:

        if config('haproxy-server-timeout'):
            ctxt['haproxy_server_timeout'] = config('haproxy-server-timeout')

        if config('haproxy-client-timeout'):
            ctxt['haproxy_client_timeout'] = config('haproxy-client-timeout')