patch 9.1.0457: tests: test_gui fails on Wayland

v:windowid is set in GUI buils with Wayland

Problem:  tests: test_gui fails on Wayland
          (after: 9.1.0064, Gary Johnson)
Solution: drop the "empty($WAYLAND_DISPLAY)" condition in the test

fixes: #14886

Signed-off-by: Christian Brabandt <cb@256bit.org>

src/testdir/test_gui.vim

@@ -899,7 +899,7 @@ func Test_set_term()
 endfunc
 
 func Test_windowid_variable()
-  if (g:x11_based_gui && empty($WAYLAND_DISPLAY)) || has('win32')
+  if g:x11_based_gui || has('win32')
     call assert_true(v:windowid > 0)
   else
     call assert_equal(0, v:windowid)

src/version.c

@@ -704,6 +704,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    457,
 /**/
     456,
 /**/