patch 9.1.1235: cproto files are outdated

Problem:  cproto files are outdated
Solution: regenerate proto files by running make proto
          (Yegappan Lakshmanan)

closes: #16956

Signed-off-by: Yegappan Lakshmanan <yegappan@yahoo.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/proto/charset.pro b/src/proto/charset.pro
index bf1fc10..c9af1b0 100644
--- a/src/proto/charset.pro
+++ b/src/proto/charset.pro
@@ -1,7 +1,7 @@
 /* charset.c */
 int init_chartab(void);
 int buf_init_chartab(buf_T *buf, int global);
-int check_isopt(char_u *isopt);
+int check_isopt(char_u *var);
 void trans_characters(char_u *buf, int bufsize);
 char_u *transstr(char_u *s);
 char_u *str_foldcase(char_u *str, int orglen, char_u *buf, int buflen);