Don't override scheduled schedules with the new ones

[yhabteab]

Fixes a daemon crash when reloading the schedules after 5m.

Removing Schedule1 as it either no longer exists in the database or its config has been changed
PHP Fatal error:  Uncaught InvalidArgumentException: Task Schedule1 not scheduled in /usr/local/src/ipl-scheduler/src/Scheduler.php:159
Stack trace:
#0 /usr/share/icingaweb2-modules/reporting/application/clicommands/ScheduleCommand.php(63): ipl\Scheduler\Scheduler->remove(Object(Icinga\Module\Reporting\Schedule))
#1 /usr/share/icinga-php/vendor/vendor/react/event-loop/src/ExtEvLoop.php(144): Icinga\Module\Reporting\Clicommands\ScheduleCommand->Icinga\Module\Reporting\Clicommands\{closure}(Object(React\EventLoop\Timer\Timer))
#2 [internal function]: React\EventLoop\ExtEvLoop->React\EventLoop\{closure}()
#3 /usr/share/icinga-php/vendor/vendor/react/event-loop/src/ExtEvLoop.php(208): EvLoop->run(2)
#4 /usr/share/icinga-php/vendor/vendor/react/event-loop/src/Loop.php(55): React\EventLoop\ExtEvLoop->run()
#5 [internal function]: React\EventLoop\Loop::React\EventLoop\{closure}()
#6 {main}
  thrown in /usr/local/src/ipl-scheduler/src/Scheduler.php on line 159