patch 8.0.1002: unnecessarily updating screen after timer callback

Problem:    Unnecessarily updating screen after timer callback.
Solution:   Check if calling the timer sets must_redraw.
diff --git a/src/version.c b/src/version.c
index f8eb491..d79f429 100644
--- a/src/version.c
+++ b/src/version.c
@@ -770,6 +770,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1002,
+/**/
     1001,
 /**/
     1000,