Dropped dependency on libgcrypt with new GnuTLS (>2.12.20) versions

src/testcurl/https/test_empty_response.c

@@ -28,7 +28,9 @@
 #include <limits.h>
 #include <sys/stat.h>
 #include <curl/curl.h>
+#ifdef MHD_HTTPS_REQUIRE_GRYPT
 #include <gcrypt.h>
+#endif /* MHD_HTTPS_REQUIRE_GRYPT */
 #include "tls_test_common.h"
 
 extern const char srv_key_pem[];