patch 8.0.0211: cannot build without the multi-byte feature

Problem:    Build fails if the multi-byte feature is disabled.
Solution:   Change #ifdef around ins_char_bytes.
diff --git a/src/version.c b/src/version.c
index 927825c..8e33c96 100644
--- a/src/version.c
+++ b/src/version.c
@@ -765,6 +765,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    211,
+/**/
     210,
 /**/
     209,