ZP-1152 Net/SMTP.php: Update to the PHP 3.01 version of the PHP license

Upstream commit 8cc6933.
No functional change.

Released under the Affero GNU General Public License (AGPL) version 3.

src/backend/imap/Net/SMTP.php

@@ -5,10 +5,10 @@
 // +----------------------------------------------------------------------+
 // | Copyright (c) 1997-2015 The PHP Group                                |
 // +----------------------------------------------------------------------+
-// | This source file is subject to version 2.02 of the PHP license,      |
+// | This source file is subject to version 3.01 of the PHP license,      |
 // | that is bundled with this package in the file LICENSE, and is        |
 // | available at through the world-wide-web at                           |
-// | http://www.php.net/license/2_02.txt.                                 |
+// | http://www.php.net/license/3_01.txt.                                 |
 // | If you did not receive a copy of the PHP license and are unable to   |
 // | obtain it through the world-wide-web, please send a note to          |
 // | license@php.net so we can mail you a copy immediately.               |