PHP warning `wp_get_sites()` is deprecated in Postman/PostmanInstaller.php

Just a small deprecation warning for wp_get_sites()

[20-Sep-2016 22:00:15 UTC] PHP Notice:  wp_get_sites is <strong>deprecated</strong> since version 4.6.0! Use get_sites() instead. in /home/ubuntu/workspace/wp-includes/functions.php on line 3707
[20-Sep-2016 22:00:15 UTC] PHP Stack trace:
[20-Sep-2016 22:00:15 UTC] PHP   1. {main}() /home/ubuntu/workspace/wp-admin/network/plugins.php:0
[20-Sep-2016 22:00:15 UTC] PHP   2. require() /home/ubuntu/workspace/wp-admin/network/plugins.php:16
[20-Sep-2016 22:00:15 UTC] PHP   3. activate_plugin($plugin = *uninitialized*, $redirect = *uninitialized*, $network_wide = *uninitialized*, $silent = *uninitialized*) /home/ubuntu/workspace/wp-admin/plugins.php:42
[20-Sep-2016 22:00:15 UTC] PHP   4. include_once() /home/ubuntu/workspace/wp-admin/includes/plugin.php:560
[20-Sep-2016 22:00:15 UTC] PHP   5. postman_start($startingMemory = *uninitialized*) /home/ubuntu/workspace/wp-content/plugins/postman-smtp/postman-smtp.php:57
[20-Sep-2016 22:00:15 UTC] PHP   6. postman_setupPostman() /home/ubuntu/workspace/wp-content/plugins/postman-smtp/postman-smtp.php:42
[20-Sep-2016 22:00:15 UTC] PHP   7. Postman->__construct($rootPluginFilenameAndPath = *uninitialized*, $version = *uninitialized*) /home/ubuntu/workspace/wp-content/plugins/postman-smtp/postman-smtp.php:51
[20-Sep-2016 22:00:15 UTC] PHP   8. PostmanInstaller->activatePostman() /home/ubuntu/workspace/wp-content/plugins/postman-smtp/Postman/Postman.php:103
[20-Sep-2016 22:00:15 UTC] PHP   9. wp_get_sites($args = *uninitialized*) /home/ubuntu/workspace/wp-content/plugins/postman-smtp/Postman/PostmanInstaller.php:32
[20-Sep-2016 22:00:15 UTC] PHP  10. _deprecated_function($function = *uninitialized*, $version = *uninitialized*, $replacement = *uninitialized*) /home/ubuntu/workspace/wp-includes/ms-deprecated.php:472
[20-Sep-2016 22:00:15 UTC] PHP  11. trigger_error(*uninitialized*) /home/ubuntu/workspace/wp-includes/functions.php:3707