stream_client_socket::operator>> forms invalid std::string on write #91

The operator>> of socket forms incorrect std::string.
If I try to read message from socket with >> I get "nothing", because std::string was not resized properly. See the code snippet below:

    // Assume that client sends "test message" after connection
    
    libsocket::inet_stream_server server("127.0.0.1", "8080", LIBSOCKET_IPv4);

    auto client = server.accept2();
   
    std::string received_msg;
    *client >> received_msg;

   // Next line prints `[SERVER] Received: `
   std::cout << "[SERVER] Received: " << received_msg << std::endl;   

   // Next line prints `[SERVER] Received: test message`
   std::cout << "[SERVER] Received: " << received_msg.data() << std::endl;

As I understood problem hides in

The condition read_bytes < static_cast<ssize_t>(dest.size()) doesn't work for case, when dest is a newly created std::string and read_bytes is greater than 0.

I suggest to remove if statement and always resize dest to read_bytes size or just invert the condition.

I will create the PR for this issue later.