return an integer in SleepDeferrer->getCurrentTime

[digibart]

because according to php documentation round() returns a float

on PHP v7.3.2 Windows this throws an exception:

 Symfony\Component\Debug\Exception\FatalThrowableError  : Return value of Spatie\GuzzleRateLimiterMiddleware\SleepDeferrer::getCurrentTime() must be of the type int, float returned

  at C:\xampp\httpdocs\vendor\spatie\guzzle-rate-limiter-middleware\src\SleepDeferrer.php:9
     5| class SleepDeferrer implements Deferrer
     6| {
     7|     public function getCurrentTime(): int
     8|     {
  >  9|         return round(microtime(true) * 1000);
    10|     }
    11|
    12|     public function sleep(int $milliseconds)
    13|     {

[digibart]

hmzz.. on a 32bit system PHP_INT_MAX is 2147483647, that is less then current microtime 1573737486894.

thus, casting it to integer is wrong on a 32 bit system.

I guess 32bit is obsolete, or at least deprecated