patch 8.0.1503: access memory beyond end of string

Problem:    Access memory beyond end of string. (Coverity)
Solution:   Keep allocated memory in separate pointer.  Avoid outputting the
            NUL character.

src/version.c

@@ -771,6 +771,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1503,
 /**/
     1502,
 /**/