patch 8.2.3440: recover test fails if there is an old swap file

Problem:    Recover test fails if there is an old swap file.
Solution:   Delete old swap files.
diff --git a/src/version.c b/src/version.c
index 47afced..0598475 100644
--- a/src/version.c
+++ b/src/version.c
@@ -756,6 +756,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    3440,
+/**/
     3439,
 /**/
     3438,