[ticket/15322] Add config setting for -f parameter & remove mail function name

The -f parameter can now be added via configuration in the ACP. Addtionally,
the config setting for the mail function name has been removed.

PHPBB3-15322

phpBB/phpbb/db/migration/data/v32x/email_envelope_sender.php

@@ -0,0 +1,37 @@
+<?php
+/**
+*
+* This file is part of the phpBB Forum Software package.
+*
+* @copyright (c) phpBB Limited <https://www.phpbb.com>
+* @license GNU General Public License, version 2 (GPL-2.0)
+*
+* For full copyright and license information, please see
+* the docs/CREDITS.txt file.
+*
+*/
+
+namespace phpbb\db\migration\data\v32x;
+
+class email_envelope_sender extends \phpbb\db\migration\migration
+{
+	static public function depends_on()
+	{
+		return array(
+			'\phpbb\db\migration\data\v32x\v321',
+		);
+	}
+
+	public function effectively_installed()
+	{
+		return isset($this->config['email_envelope_sender']);
+	}
+
+	public function update_data()
+	{
+		return array(
+			array('config.add', array('email_envelope_sender', '0')),
+			array('config.remove', array('email_function_name')),
+		);
+	}
+}