Correct usage of MysteryEvent to MysteryGift

src/trade.c

@@ -19,8 +19,8 @@
 #include "load_save.h"
 #include "mail.h"
 #include "main.h"
-#include "mevent.h"
 #include "mystery_gift.h"
+#include "mystery_gift_menu.h"
 #include "overworld.h"
 #include "palette.h"
 #include "party_menu.h"