patch 9.0.1313: some settings use the current codepage instead of 'encoding'

Problem:    Some settings use the current codepage instead of 'encoding'.
Solution:   Adjust how options are initialized. (Ken Takata, closes #11992)
diff --git a/src/proto/misc1.pro b/src/proto/misc1.pro
index 167805b..5884821 100644
--- a/src/proto/misc1.pro
+++ b/src/proto/misc1.pro
@@ -26,6 +26,7 @@
 void init_homedir(void);
 void free_homedir(void);
 void free_users(void);
+void init_vimdir(void);
 char_u *expand_env_save(char_u *src);
 char_u *expand_env_save_opt(char_u *src, int one);
 void expand_env(char_u *src, char_u *dst, int dstlen);