patch 8.0.1242: function argument with only dash is seen as number zero

Problem:    Function argument with only dash is seen as number zero. (Wang
            Shidong)
Solution:   See a dash as a string. (Christian Brabandt)

src/version.c

@@ -761,6 +761,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1242,
 /**/
     1241,
 /**/