CSocket: Don't create the read notifier until after we've connected

This makes it so that "on_connected" always gets called first.
Since accepted sockets are connected before construction, they have
to manually set CSocket::m_connected.

Libraries/LibCore/CLocalSocket.cpp

@@ -5,6 +5,8 @@
 CLocalSocket::CLocalSocket(int fd, CObject* parent)
     : CSocket(CSocket::Type::Local, parent)
 {
+    // NOTE: This constructor is used by CLocalServer::accept(), so the socket is already connected.
+    m_connected = true;
     set_fd(fd);
     set_mode(CIODevice::ReadWrite);
     set_error(0);