[8771] Fixed *nix build and small code cleanup.

Thanks to balrok for reporting, and help in resolve/test.

src/game/SharedDefines.h

@@ -2620,27 +2620,6 @@ enum BattleGroundTypeId
 };
 #define MAX_BATTLEGROUND_TYPE_ID 33
 
-enum MailCheckMask
-{
-    MAIL_CHECK_MASK_NONE        = 0x00,
-    MAIL_CHECK_MASK_READ        = 0x01,
-    MAIL_CHECK_MASK_AUCTION     = 0x04,
-    MAIL_CHECK_MASK_COD_PAYMENT = 0x08,
-    MAIL_CHECK_MASK_RETURNED    = 0x10
-};
-
-// gathered from Stationery.dbc
-enum MailStationery
-{
-    MAIL_STATIONERY_UNKNOWN =  1,
-    MAIL_STATIONERY_NORMAL  = 41,
-    MAIL_STATIONERY_GM      = 61,
-    MAIL_STATIONERY_AUCTION = 62,
-    MAIL_STATIONERY_VAL     = 64,
-    MAIL_STATIONERY_CHR     = 65,
-    MAIL_STATIONERY_ORP     = 67,                           // new in 3.2.2
-};
-
 enum MailResponseType
 {
     MAIL_SEND               = 0,