patch 8.0.1770: assert functions don't return anything

Problem:    Assert functions don't return anything.
Solution:   Return non-zero when the assertion fails.

src/version.c

@@ -761,6 +761,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1770,
 /**/
     1769,
 /**/