Only call setAdvertisedNextProtocols() if it is available

Author: simpkins

rsocket/transports/tcp/TcpConnectionFactory.cpp

@@ -44,7 +44,9 @@ class ConnectCallback : public folly::AsyncSocket::ConnectCallback {
 
     if (sslContext) {
       VLOG(3) << "Starting SSL socket";
+#if FOLLY_OPENSSL_HAS_ALPN
       sslContext->setAdvertisedNextProtocols({"rs"});
+#endif // FOLLY_OPENSSL_HAS_ALPN
       socket_.reset(new folly::AsyncSSLSocket(sslContext, evb));
     } else {
       VLOG(3) << "Starting socket";