patch 8.1.0442: GUI: cursor not drawn after ":redraw | sleep"

Problem:    GUI: Cursor not drawn after ":redraw | sleep".
Solution:   Flush the output. (closes #3496)
diff --git a/src/version.c b/src/version.c
index c81491d..f3a72ec 100644
--- a/src/version.c
+++ b/src/version.c
@@ -795,6 +795,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    442,
+/**/
     441,
 /**/
     440,