[BUGFIX] Followup: Exception when configured replyEmail is empty

Fixed a parse error

Change-Id: Ib8366d51057a61ff3e89b7848bbf762bb4575a31
Resolves: #63895
Releases: 6.2
Reviewed-on: http://review.typo3.org/35473
Reviewed-by: Sebastian Fischer <typo3@evoweb.de>
Tested-by: Sebastian Fischer <typo3@evoweb.de>