get ips () {
    const proxy = this.app.proxy
    const val = this.get(this.app.proxyIpHeader)
    let ips = proxy && val
      ? splitCommaSeparatedValues(val)
      : []
    if (this.app.maxIpsCount > 0) {
      ips = ips.slice(-this.app.maxIpsCount)
    }
    return ips
  }
When `app.proxy` is `true`, parse
the "X-Forwarded-For" ip address list.

For example if the value was "client, proxy1, proxy2"
you would receive the array `["client", "proxy1", "proxy2"]`
where "proxy2" is the furthest down-stream.

@return {Array}
@api public