`test_email_notification` test fails if MDL-85366 is backported

[djarran]

Description: Following test is failing

1) mod_facetoface\session_test::test_email_notification with data set "email with message: html message and html details with type: both" (3, '\n            <p> This is the...      ', '\n            <p> This is a h...      ', 2, 1, '<div class="text_to_html"><br...</div>')
Failed asserting that actual size 0 matches expected size 1.

/var/www/site/mod/facetoface/tests/session_test.php:284
/var/www/site/lib/phpunit/classes/advanced_testcase.php:76