openssl_stream: use new initialization function on OpenSSL version >=1.1

Previous to OpenSSL version 1.1, the user had to initialize at least the error
strings as well as the SSL algorithms by himself. OpenSSL version 1.1 instead
provides a new function `OPENSSL_init_ssl`, which handles initialization of all
subsystems. As the new API call will by default load error strings and
initialize the SSL algorithms, we can safely replace these calls when compiling
against version 1.1 or later.

This fixes a compiler error when compiling against OpenSSL version 1.1 which has
been built without stubs for deprecated syntax.

src/openssl_stream.c

@@ -103,8 +103,13 @@ int git_openssl_stream_global_init(void)
 	ssl_opts |= SSL_OP_NO_COMPRESSION;
 #endif
 
+#if OPENSSL_VERSION_NUMBER < 0x10100000L
 	SSL_load_error_strings();
 	OpenSSL_add_ssl_algorithms();
+#else
+	OPENSSL_init_ssl(0, NULL);
+#endif
+
 	/*
 	 * Load SSLv{2,3} and TLSv1 so that we can talk with servers
 	 * which use the SSL hellos, which are often used for