patch 9.0.1440: "rvim" can execute a shell through :diffpatch

Problem:    "rvim" can execute a shell through :diffpatch.
Solution:   Disallow the shell "patch" command.
diff --git a/src/version.c b/src/version.c
index 5cace2e3..853ea5f 100644
--- a/src/version.c
+++ b/src/version.c
@@ -696,6 +696,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1440,
+/**/
     1439,
 /**/
     1438,