Remove duplicate decl; use EASY_CHAT_TYPE define in mystery_event_club.inc

include/easy_chat.h

@@ -30,7 +30,6 @@ struct EasyChatWordsByLetter
     int numWords;
 };
 
-void InitEasyChatPhrases(void);
 u8 *CopyEasyChatWord(u8 *dest, u16 word);
 u8 *ConvertEasyChatWordsToString(u8 *dest, const u16 *src, u16 length1, u16 length2);
 bool8 EC_DoesEasyChatStringFitOnLine(const u16 *easyChatWords, u8 columns, u8 rows, u16 maxLength);