patch 8.0.1352: dead URLs in the help go unnoticed

Problem:    Dead URLs in the help go unnoticed.
Solution:   Add a script to check URLs in the help files. (Christian Brabandt)
diff --git a/src/version.c b/src/version.c
index 14e5083..da4ad06 100644
--- a/src/version.c
+++ b/src/version.c
@@ -772,6 +772,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1352,
+/**/
     1351,
 /**/
     1350,