patch 8.2.3389: cannot stop insert mode completion without side effects

Problem:    Cannot stop insert mode completion without side effects.
Solution:   Add CTRL-X CTRL-Z. (closes #8821)
diff --git a/src/version.c b/src/version.c
index 7aef272..fd854d5 100644
--- a/src/version.c
+++ b/src/version.c
@@ -756,6 +756,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    3389,
+/**/
     3388,
 /**/
     3387,