patch 8.0.1661: warnings from 64 bit compiler

Problem:    Warnings from 64 bit compiler.
Solution:   Add type casts. (Mike Williams)
diff --git a/src/version.c b/src/version.c
index 2d566ca..87a326a 100644
--- a/src/version.c
+++ b/src/version.c
@@ -763,6 +763,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1661,
+/**/
     1660,
 /**/
     1659,