patch 9.0.1557: test failures for unreachable code

Problem:    Test failures for unreachable code.
Solution:   Add a test override to ignore unreachable code.

src/version.c

@@ -695,6 +695,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1557,
 /**/
     1556,
 /**/