Protocol/Smtp/Auth classes have different signature than parent class

[rarog]

Bug Report

Q	A
Version(s)	2.14.1

Summary

All classes in Protocol/Smtp/Auth have less strict signature than parent class without profiting from it.

Current behavior

Current signature is public function __construct($host = '127.0.0.1', $port = null, $config = null) while Protocol/Smtp has the signature public function __construct($host = '127.0.0.1', $port = null, array $config = null).
As the original parameter is passed on as is to the parent class, $config should also be forced to be of type array to match and enforce correctness.