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

src/version.c

@@ -695,6 +695,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1039,
 /**/
     1038,
 /**/