patch 8.1.1864: still a timer test that is flaky on Mac

Problem:    Still a timer test that is flaky on Mac.
Solution:   Adjust the sleep times.
diff --git a/src/version.c b/src/version.c
index 3adfdd0..f3de68b 100644
--- a/src/version.c
+++ b/src/version.c
@@ -770,6 +770,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1864,
+/**/
     1863,
 /**/
     1862,