TCPServer: optimized internal write buffers

src/stratum_server.cpp

@@ -758,7 +758,7 @@ void StratumServer::on_blobs_ready()
 			}
 
 			const bool result = send(client,
-				[data, target, hashing_blob, &job_id](void* buf, size_t buf_size)
+				[data, target, hashing_blob, job_id](void* buf, size_t buf_size)
 				{
 					log::hex_buf target_hex(reinterpret_cast<const uint8_t*>(&target), sizeof(uint64_t));