patch 8.1.0161: buffer not updated with 'autoread' set if file was deleted

Problem:    Buffer not updated with 'autoread' set if file was deleted.
            (Michael Naumann)
Solution:   Don't set the timestamp to zero. (closes #3165)
diff --git a/src/version.c b/src/version.c
index cb6d2c8..affeeb2 100644
--- a/src/version.c
+++ b/src/version.c
@@ -790,6 +790,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    161,
+/**/
     160,
 /**/
     159,