Author: Eloy Lafuente (stronk7)
MDL-63421 env: Moodle 3.4.x and 3.5.x do not support PHP 7.3
http://git.moodle.org/gw?p=moodle.git;a=commit;h=6ef7759473187c813807d5dc9b37b43ac39964a8
http://github.com/moodle/moodle/commit/6ef7759473187c813807d5dc9b37b43ac39964a8
+ 3.3 en [unsupportedphpversion73,core_admin]