patch 8.0.1018: warnings from 64-bit compiler

Problem:    Warnings from 64-bit compiler. (Christian Brabandt)
Solution:   Add type casts.
diff --git a/src/version.c b/src/version.c
index e4de8c1..d18585d 100644
--- a/src/version.c
+++ b/src/version.c
@@ -770,6 +770,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1018,
+/**/
     1017,
 /**/
     1016,