COMP: Support building in RelWithDebInfo configuration on Windows
Created by: msmolens
This commit fixes build errors when building in the RelWithDebInfo configuration on Windows. Previously, projects that use OpenSSL_DIR would fail to find the OpenSSL headers because only 'Debug' and 'Release' directories--not 'RelWithDebInfo'--are provided by the precompiled OpenSSL binaries.
An example error is:
10>C:\S\R\Python-2.7.11\Modules\_hashopenssl.c(39): fatal error C1083: Cannot open include file: 'openssl/evp.h': No such file or directory