patch 8.0.0498: two autocmd tests are skipped on MS-Windows

Problem:    Two autocmd tests are skipped on MS-Windows.
Solution:   Make the test pass on MS-Windows. Write the messages in a file
            instead of getting the output of system().

src/version.c

@@ -764,6 +764,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    498,
 /**/
     497,
 /**/