Second attempt to silence SSL compile failures on hamerkop.

Second attempt to silence SSL compile failures on hamerkop.

After further investigation, it seems the cause of the problem
is our recent decision to start defining WIN32_LEAN_AND_MEAN.
That causes <windows.h> to no longer include <wincrypt.h>, which
means that the OpenSSL headers are unable to prevent conflicts
with that header by #undef'ing the conflicting macros.  Apparently,
some other system header that be-secure-openssl.c #includes after
the OpenSSL headers is pulling in <wincrypt.h>.  It's obscure just
where that happens and why we're not seeing it on other Windows
buildfarm animals.  However, it should work to move the OpenSSL
#includes to the end of the list.  For the sake of future-proofing,
do likewise in fe-secure-openssl.c.  In passing, remove useless
double inclusions of <openssl/ssl.h>.

Thanks to Thomas Munro for running down the relevant information.

Discussion: https://postgr.es/m/1051867.1635720347@sss.pgh.pa.us