[BUGFIX] Use integer instead of strings as default for new Mail config

Default values should be integer for the newly
introduced MAIL options in
https://review.typo3.org/c/Packages/TYPO3.CMS/+/69907

Resolves: #96803
Related: #94544
Releases: main
Change-Id: I1cbced77304e3015e5d5c64fde7257d46f037eb5
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/73373


Tested-by: Oliver Hader <oliver.hader@typo3.org>
Tested-by: Georg Ringer <georg.ringer@gmail.com>
Tested-by: core-ci <typo3@b13.com>
Tested-by: Benni Mack <benni@typo3.org>
Reviewed-by: Oliver Hader <oliver.hader@typo3.org>
Reviewed-by: Georg Ringer <georg.ringer@gmail.com>
Reviewed-by: Benni Mack <benni@typo3.org>