Does not work with 1.6.26

[kromonos]

Headers are missing and cli commands are throwing errors:

$ bin/plugin webmention notify
PHP Fatal error:  Uncaught Error: Call to undefined method Grav\Plugin\Console\NotifyCommand::getgrav() in /var/customers/webs/kromonos/example.com/user/plugins/webmention/cli/NotifyCommand.php:68
Stack trace:
#0 /var/customers/webs/kromonos/example.com/system/src/Grav/Console/ConsoleCommand.php(41): Grav\Plugin\Console\NotifyCommand->serve()
#1 /var/customers/webs/kromonos/example.com/vendor/symfony/console/Command/Command.php(255): Grav\Console\ConsoleCommand->execute(Object(Symfony\Component\Console\Input\ArgvInput), Object(Symfony\Component\Console\Output\ConsoleOutput))
#2 /var/customers/webs/kromonos/example.com/vendor/symfony/console/Application.php(917): Symfony\Component\Console\Command\Command->run(Object(Symfony\Component\Console\Input\ArgvInput), Object(Symfony\Component\Console\Output\ConsoleOutput))
#3 /var/customers/webs/kromonos/example.com/vendor/symfony/console/Application.php(269): Symfony\Component\Console\Application->doRunCommand(Object(Grav\Plugin\Console\NotifyCommand), Object(Symfony\Component\Con in /var/customers/webs/kromonos/example.com/user/plugins/webmention/cli/NotifyCommand.php on line 68

Looks like data_sent.yaml is filled as normal