patch 8.0.1700: coverage statistics still don't work on coveralls

Problem:    Coverate statistics still don't work on coveralls.
Solution:   Exclude the xxd directory again.

src/version.c

@@ -762,6 +762,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1700,
 /**/
     1699,
 /**/