Merge branch 'ms-fix-service-desk-handler-without-to-address' into 'master'

Fixes error when mail without TO header in ServiceDeskHandler

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/132913



Merged-by: Tetiana Chupryna <tchupryna@gitlab.com>
Approved-by: Tetiana Chupryna <tchupryna@gitlab.com>
Reviewed-by: Tetiana Chupryna <tchupryna@gitlab.com>
Reviewed-by: Marc Saleiko <msaleiko@gitlab.com>
Co-authored-by: Marc Saleiko <msaleiko@gitlab.com>