build: Remove unnecessary std::ref, causing compilation issues with Boost 1.70.0

Refs: #4923
Change-Id: Idba1abe89161b11b1ec80fdceac51e2b00ed507b
diff --git a/daemon/face/tcp-channel.cpp b/daemon/face/tcp-channel.cpp
index dc0576f..a26c91e 100644
--- a/daemon/face/tcp-channel.cpp
+++ b/daemon/face/tcp-channel.cpp
@@ -83,7 +83,7 @@
     return;
   }
 
-  auto clientSocket = make_shared<ip::tcp::socket>(std::ref(getGlobalIoService()));
+  auto clientSocket = make_shared<ip::tcp::socket>(getGlobalIoService());
   auto timeoutEvent = getScheduler().schedule(timeout, [=] {
     handleConnectTimeout(remoteEndpoint, clientSocket, onConnectFailed);
   });