patch 9.0.1040: test for <Cmd> mapping with CmdlineChanged fails

Problem:    Test for <Cmd> mapping with CmdlineChanged fails.
Solution:   Put back the check for the cmdline length not changing.
diff --git a/src/version.c b/src/version.c
index bfa0c5d..5e0bf4f 100644
--- a/src/version.c
+++ b/src/version.c
@@ -696,6 +696,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1040,
+/**/
     1039,
 /**/
     1038,