[FIX] wikiplugin_mail : Fix TypeError for the 'mail_user' parameter
requested to merge amaninyumu1/tiki:fix-error-implode-Argument-2-must-be-of-type-array-string-given-27.x into 27.x
- [FIX] wikiplugin_mail : Fix TypeError for the 'mail_user' parameter
See merge request !4861 (merged)
(cherry picked from commit 2c3879d4)