Fixes RODEX retrieve all button (#5238)

* Fixes #5061.
* Resolves the client crashing when attempting to retrieve all attachments from mail.
* Mail should not be marked as read after retrieving the attachments from them.
* Converts packets to new struct format.
Thanks to @admkakaroto and @attackjom!

src/char/char.cpp

@@ -2767,6 +2767,7 @@ void char_set_defaults(){
 	charserv_config.clan_remove_inactive_days = 14;
 	charserv_config.mail_return_days = 14;
 	charserv_config.mail_delete_days = 14;
+	charserv_config.mail_retrieve = 1;
 
 #if defined(RENEWAL) && PACKETVER >= 20151001
 	charserv_config.allowed_job_flag = 3;