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.

src/testdir/test_recover.vim

@@ -170,6 +170,12 @@ func Test_recover_empty_swap_file()
   call assert_match('Unable to read block 0 from .Xfile1.swp', msg)
   call assert_equal('Xfile1', @%)
   bw!
+
+  " make sure there are no old swap files laying around
+  for f in glob('.sw?', 0, 1)
+    call delete(f)
+  endfor
+
   " :recover from an empty buffer
   call assert_fails('recover', 'E305:')
   call delete('.Xfile1.swp')

src/version.c

@@ -755,6 +755,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    3440,
 /**/
     3439,
 /**/