regerror.c: lenghten MAX_ERROR_PAR_LEN to contain old property names

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@65095 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

regerror.c

@@ -242,8 +242,8 @@ static int to_ascii(OnigEncoding enc, UChar *s, UChar *end,
 }
 
 
-/* for ONIG_MAX_ERROR_MESSAGE_LEN */
-#define MAX_ERROR_PAR_LEN   30
+/* < ONIG_MAX_ERROR_MESSAGE_LEN - max length of messages with %n */
+#define MAX_ERROR_PAR_LEN   50
 
 extern int
 onig_error_code_to_str(UChar* s, OnigPosition code, ...)