patch 9.0.1592: not all timer tests are marked as flaky

Problem:    Not all timer tests are marked as flaky.
Solution:   Set the flaky flag for all timer tests. (closes #12355)
diff --git a/src/version.c b/src/version.c
index ad1b686..45e5b58 100644
--- a/src/version.c
+++ b/src/version.c
@@ -696,6 +696,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1592,
+/**/
     1591,
 /**/
     1590,