Added a reset of the alternative_email fields when assign a watcher (or a technician or a requester)
fixes #3468

- fix failure of tests on monday between 12am and 1pm
- fix failure of tests on last 7 days of month

Signed-off-by: Thierry Bugier <tbugier@teclib.com>

Fix a regression introduced in e8999dbc

* Fix optionnal state of check_prerequisites plugins function

* Fix potential undefined var

* Fix Iterator mock in Migration::addConfig() test

* Fix error handling in unit tests

* Fix parsing of classes on Search::testSearchOptions()

==> Error E_NOTICE in /var/glpi/tests/functionnal/Search.php on line 558, generated by file /var/glpi/tests/functionnal/Search.php on line 95:
file_get_contents(): read of 8192 bytes failed with errno=21 Is a directory

* Fix notice trigerred when ticket has no followup

==> Error E_NOTICE in /var/glpi/tests/functionnal/NotificationTargetTicket.php on line 115, generated by file /var/glpi/inc/notificationtargetticket.class.php on line 462:
Trying to access array offset on value of type bool

* ldap_control_paged* are deprecated in PHP 7.4 (#6570)

* Run test suite on PHP 7.4

* Update dependencies that fixed issues with PHP 7.4

* Update blueimp-file-upload PHP handler

* Fix travis configuration

* Fix 'Trying to access array offset on value of type bool' on LDAP sync

Co-authored-by: Johan Cwiklinski <trasher@x-tnd.be>