Fix default of mail_smtpmode - fixes #3102

Signed-off-by: Morris Jobke <hey@morrisjobke.de>

config/config.sample.php

@@ -310,9 +310,9 @@ $CONFIG = array(
  * For ``qmail`` the binary is /var/qmail/bin/sendmail, and it must be installed
  * on your Unix system.
  *
- * Defaults to ``sendmail``
+ * Defaults to ``php``
  */
-'mail_smtpmode' => 'sendmail',
+'mail_smtpmode' => 'php',
 
 /**
  * This depends on ``mail_smtpmode``. Specify the IP address of your mail

lib/private/Mail/Mailer.php

@@ -200,7 +200,7 @@ class Mailer implements IMailer {
 	 * @return \Swift_SendmailTransport
 	 */
 	protected function getSendMailInstance() {
-		switch ($this->config->getSystemValue('mail_smtpmode', 'sendmail')) {
+		switch ($this->config->getSystemValue('mail_smtpmode', 'php')) {
 			case 'qmail':
 				$binaryPath = '/var/qmail/bin/sendmail';
 				break;