Disable OpenSSL hashing when using native PKCS#11
When building with "--enable-native-pkcs11 --with-openssl", OpenSSL support is automatically disabled in favor of native PKCS#11:
checking for OpenSSL library... use of native PKCS11 instead
However, adding "--enable-openssl-hash" to the above two switches causes the build to fail:
checking for OpenSSL library... use of native PKCS11 instead
disabled because of native PKCS11
checking for using OpenSSL for hash functions... configure: error: No OpenSSL for hash functions
In other words, "--with-openssl" and "--enable-openssl-hash" are not behaving consistently when used together with "--enable-native-pkcs11".
Fix by automatically disabling OpenSSL hashing support when native PKCS#11 support is enabled.