patch 8.2.3426: crash when deleting a listener in a listener callback

Problem:    Crash when deleting a listener in a listener callback. (Naohiro
            Ono)
Solution:   Mark the listener and delete it later.
diff --git a/src/version.c b/src/version.c
index 05331a6..c98249b 100644
--- a/src/version.c
+++ b/src/version.c
@@ -756,6 +756,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    3426,
+/**/
     3425,
 /**/
     3424,