patch 9.0.0447: using :echowin while at the hit-enter prompt causes problems

Problem:    Using :echowin while at the hit-enter prompt causes problems.
Solution:   Do not prompt for :echowin.  Postpone showing the message window.
            Start the timer when the window is displayed.

src/version.c

@@ -703,6 +703,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    447,
 /**/
     446,
 /**/