openssl_stream: fix building with libressl

OpenSSL v1.1 has introduced a new way of initializing the library
without having to call various functions of different subsystems. In
libgit2, we have been adapting to that change with 8852015
(openssl_stream: use new initialization function on OpenSSL version
>=1.1, 2017-04-07), where we added an #ifdef depending on the OpenSSL
version. This change broke building with libressl, though, which has not
changed its API in the same way.

Fix the issue by expanding the #ifdef condition to use the old way of
initializing with libressl.

Signed-off-by: Marc-Antoine Perennou <Marc-Antoine@Perennou.com>

Author: Keruspe

src/openssl_stream.c

@@ -103,7 +103,7 @@ int git_openssl_stream_global_init(void)
 	ssl_opts |= SSL_OP_NO_COMPRESSION;
 #endif
 
-#if OPENSSL_VERSION_NUMBER < 0x10100000L
+#if OPENSSL_VERSION_NUMBER < 0x10100000L || defined(LIBRESSL_VERSION_NUMBER)
 	SSL_load_error_strings();
 	OpenSSL_add_ssl_algorithms();
 #else