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.
diff --git a/src/version.c b/src/version.c
index 62fd9ed..5c72d8d 100644
--- a/src/version.c
+++ b/src/version.c
@@ -772,6 +772,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1503,
+/**/
     1502,
 /**/
     1501,