patch 8.1.1501: new behavior of b:changedtick not tested

Problem:    New behavior of b:changedtick not tested.
Solution:   Add a few test cases. (Daniel Hahler)
diff --git a/src/version.c b/src/version.c
index b0dcd3b..3dcf0c6 100644
--- a/src/version.c
+++ b/src/version.c
@@ -768,6 +768,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1501,
+/**/
     1500,
 /**/
     1499,