[PATCH gnupg] Fix pointer to integer cast warnings in Windows platform

[Biswapriyo Nath]

> We keep the warnings as a reminder that we need to replace all kind of
> sockets/fds/streams by estream system objects.

With clang version 15, the pointer to integer conversion warnings are
treated as errors by default[1]. That causes build failure with mingw
clang toolchain. So, do you suggest to use `-Wno-int-conversion`
compiler flag with all projects i.e. gnupg, gnutls etc. ?

[1]: https://releases.llvm.org/15.0.0/tools/clang/docs/ReleaseNotes.html