patch 8.2.5097: using uninitialized memory when using 'listchars'

Problem:    Using uninitialized memory when using 'listchars'.
Solution:   Use the length returned by mb_char2bytes(). (closes #10576)
diff --git a/src/version.c b/src/version.c
index 3ee54db..4d63c86 100644
--- a/src/version.c
+++ b/src/version.c
@@ -735,6 +735,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    5097,
+/**/
     5096,
 /**/
     5095,