[TASK] Adds notice for lockDomain option in tooltip

Notice message for lockDomain option that it can
be circumvented by faking HTTP_HOST

Resolves: #75104
Releases: master
Change-Id: I9b83ab7380123a78a2b99b8ab8127a4fcc69beb4
Reviewed-on: https://review.typo3.org/49751


Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Mona Muzaffar <mona.muzaffar@gmx.de>
Tested-by: Mona Muzaffar <mona.muzaffar@gmx.de>
Reviewed-by: Josef Glatz <josef.glatz@typo3.org>
Tested-by: Josef Glatz <josef.glatz@typo3.org>
Reviewed-by: Georg Ringer <georg.ringer@gmail.com>
Tested-by: Georg Ringer <georg.ringer@gmail.com>