patch 8.2.4821: crash when imported autoload script was deleted

Problem:    Crash when imported autoload script was deleted.
Solution:   Initialize local variable. (closes #10274)  Give a more meaningful
            error message.
diff --git a/src/version.c b/src/version.c
index 62d6e5d..36adeb6 100644
--- a/src/version.c
+++ b/src/version.c
@@ -747,6 +747,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    4821,
+/**/
     4820,
 /**/
     4819,