Timer::cancel() is obsolete

[fmdelvalle]

Curl.php lines 94 and following should be replaced with:
if (!isset($this->loop_timer)) {
$this->loop_timer = $this->loop->addPeriodicTimer($this->timeout, function() {
$this->run();
if (!($this->client->run() || $this->client->has())) {
$this->loop->cancelTimer($this->loop_timer);
$this->loop_timer = null;
}
});
}