patch 8.1.1328: no test for listener with undo operation

Problem:    No test for listener with undo operation.
Solution:   Add a test.
diff --git a/src/testdir/test_listener.vim b/src/testdir/test_listener.vim
index d0e4366..26cf2d3 100644
--- a/src/testdir/test_listener.vim
+++ b/src/testdir/test_listener.vim
@@ -21,6 +21,15 @@
   redraw
   call assert_equal([{'lnum': 1, 'end': 2, 'col': 1, 'added': 0}], s:list)
 
+  " Undo is also a change
+  set undolevels&  " start new undo block
+  call append(2, 'two two')
+  undo
+  redraw
+  call assert_equal([{'lnum': 3, 'end': 3, 'col': 1, 'added': 1},
+	\ {'lnum': 3, 'end': 4, 'col': 1, 'added': -1}, ], s:list)
+  1
+
   " Two listeners, both get called.
   let id2 = listener_add({l -> s:AnotherStoreList(l)})
   let s:list = []
diff --git a/src/version.c b/src/version.c
index d45484f..74dba7c 100644
--- a/src/version.c
+++ b/src/version.c
@@ -768,6 +768,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1328,
+/**/
     1327,
 /**/
     1326,