patch 8.2.5129: timeout handling is not optimal

Problem:    Timeout handling is not optimal.
Solution:   Avoid setting timeout_flag twice.  Adjust the pointer when
            stopping the regexp timeout.  Adjust variable name.
diff --git a/src/version.c b/src/version.c
index 75cbbaf..d038087 100644
--- a/src/version.c
+++ b/src/version.c
@@ -735,6 +735,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    5129,
+/**/
     5128,
 /**/
     5127,