patch 8.2.4120: block insert goes over the end of the line

Problem:    Block insert goes over the end of the line.
Solution:   Handle invalid byte better.  Fix inserting the wrong text.
diff --git a/src/version.c b/src/version.c
index 01b8e5d..6fda77e 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    4120,
+/**/
     4119,
 /**/
     4118,