patch 8.2.0438: terminal noblock test is very flaky on BSD

Problem:    Terminal noblock test is very flaky on BSD.
Solution:   Change WaitFor() to WaitForAssert() to be able to see why it
            failed.  Add a short wait in between sending keys.

src/version.c

@@ -738,6 +738,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    438,
 /**/
     437,
 /**/