patch 8.2.2454: leading space can not be made visible

Problem:    Leading space can not be made visible.
Solution:   Add "lead:" to 'listchars'. (closes #7772)
diff --git a/src/version.c b/src/version.c
index 679f3a5..9eb0f5d 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2454,
+/**/
     2453,
 /**/
     2452,