patch 8.2.3669: buffer overflow with long help argument

Problem:    Buffer overflow with long help argument.
Solution:   Use snprintf().
diff --git a/src/version.c b/src/version.c
index a225e18..da5871e 100644
--- a/src/version.c
+++ b/src/version.c
@@ -758,6 +758,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    3669,
+/**/
     3668,
 /**/
     3667,