patch 9.0.1039: using a <Cmd> mapping CmdlineChanged may be triggered twice

Problem:    Using a <Cmd> mapping CmdlineChanged may be triggered twice.
Solution:   Count the number of times CmdlineChanged is triggered and avoid
            doing it twice. (closes #116820
diff --git a/src/version.c b/src/version.c
index aac1cc9..bfa0c5d 100644
--- a/src/version.c
+++ b/src/version.c
@@ -696,6 +696,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1039,
+/**/
     1038,
 /**/
     1037,