[mod_secdownload] fix compile w/ NSS on FreeBSD
(thx dirk)
nss/alghmac.h might not exist
#elif defined(USE_WOLFSSL_CRYPTO)
#include <wolfssl/wolfcrypt/hmac.h>
#elif defined(USE_NSS_CRYPTO)
+#if 0 /*(nss/alghmac.h might not be present)*/
#ifdef NSS_VER_INCLUDE
#include <nss3/alghmac.h>
#else
#endif
#endif
#endif
+#endif
#if defined(USE_OPENSSL_CRYPTO) && OPENSSL_VERSION_NUMBER >= 0x30000000L
#define HMAC EVP_HMAC
