Revert changes in test file

This reverts changes made in 2f70038 and 4fcaebb. This test is
supposed to run
only on Windows indeed, as in a Unix environment with a mail server
configured,
an email will be send. On Windows, only emptying the SMTP ini directives
is enough.

Author: carusogabriel

ext/standard/tests/mail/bug69115.phpt

@@ -1,5 +1,7 @@
 --TEST--
 Bug #69115 crash in mail (plus indirect pcre test)
+--SKIPIF--
+<?php if (substr(PHP_OS, 0, 3) !== 'WIN') die('skip Windows only test, as in Unix builds it sends an email'); ?>
 --INI--
 SMTP = 
 smtp_port =
@@ -12,3 +14,4 @@ mail('user@example.com', 'My Subject', $message, "From: me@me.me");
 ===DONE===
 --EXPECTREGEX--
 .*
+===DONE===