[BUGFIX] Fix translation for emailCreateNotifyText1/2

Currently those strings mention an "invitation".
Of course this needs to be "creation" instead.

Change-Id: If0d5b4cfc6bae9161758b0eab55f0045c78c3994
Resolves: #60401
Reviewed-on: https://review.typo3.org/31691
Reviewed-by: Alex Kellner <alexander.kellner@einpraegsam.net>
Tested-by: Alex Kellner <alexander.kellner@einpraegsam.net>