Remove sometimes inaccurate error hint about source of wrongly encoded data.

src/backend/utils/mb/wchar.c

 /*
  * conversion functions between pg_wchar and multibyte streams.
  * Tatsuo Ishii
- * $PostgreSQL: pgsql/src/backend/utils/mb/wchar.c,v 1.73 2009/06/11 14:49:05 momjian Exp $
+ * $PostgreSQL: pgsql/src/backend/utils/mb/wchar.c,v 1.74 2010/01/04 20:38:31 adunstan Exp $
  *
  */
 /* can be used in either frontend or backend */
@@ -1608,10 +1608,7 @@ report_invalid_encoding(int encoding, const char *mbstr, int len)
 			(errcode(ERRCODE_CHARACTER_NOT_IN_REPERTOIRE),
 			 errmsg("invalid byte sequence for encoding \"%s\": 0x%s",
 					pg_enc2name_tbl[encoding].name,
-					buf),
-		  errhint("This error can also happen if the byte sequence does not "
-			"match the encoding expected by the server, which is controlled "
-				  "by \"client_encoding\".")));
+					buf)));
 }
 
 /*