minor fixes for Windows

- fix to use secure URL in generated Windows resources
- fix a potentially uninitialized variable
- fix an unused variable warning

CLA: trivial

Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Paul Dale <paul.dale@oracle.com>
Reviewed-by: Matthias St. Pierre <Matthias.St.Pierre@ncp-e.com>
(Merged from https://github.com/openssl/openssl/pull/7189)