patch 8.2.3321: some code is not tested

Problem:    Some code is not tested.
Solution:   Add some more tests. (Dominique Pellé, closes #8735)
diff --git a/src/version.c b/src/version.c
index 43ff156..ffe37a4 100644
--- a/src/version.c
+++ b/src/version.c
@@ -756,6 +756,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    3321,
+/**/
     3320,
 /**/
     3319,