Use repr for 2S text.

session.cpp

@@ -545,10 +545,11 @@ void Session::to_server(const std::string &message) {
 
 void Session::to_server(const std::string &message, const std::string &source) {
   auto self(shared_from_this());
+  std::string work = repr(message);
   if (source.empty())
-    BUGZ_LOG(trace) << "2S: " << message;
+    BUGZ_LOG(trace) << "2S: " << work;
   else
-    BUGZ_LOG(trace) << source << " 2S: " << message;
+    BUGZ_LOG(trace) << source << " 2S: " << work;
 
   boost::asio::async_write(
       server_, boost::asio::buffer(message),