Fix: Preventing Divide by zero when $value->getSize() is called

When using min:0 in validation rule, Laravel throws an Exception SplFileInfo::getSize():  stat failed for [filename]. 

It would be ideal to ensure that the Validator getSize function prevents the scenario from taking place, by checking that a valid file exists and that no empty file is evaluated to trigger the above exception.
Why `(int)false`? Just do `0`.