Fixed compile on gcc 3.4 and later. gcc started doing access checks

for class visibility on pointers to member function 'using the
qualifying scope of the name itself.'  what this means is if method
'prot' is declared protected in class A and B inherits from A then
a method in B cannot use &A::prot but can use &B::prot.  Synergy
now does this in the one place it had not.

lib/platform/CXWindowsScreen.cpp

@@ -169,8 +169,8 @@ CXWindowsScreen::CXWindowsScreen(bool isPrimary) :
 
 	// install event handlers
 	EVENTQUEUE->adoptHandler(CEvent::kSystem, IEventQueue::getSystemTarget(),
-							new TMethodEventJob<IPlatformScreen>(this,
-								&IPlatformScreen::handleSystemEvent));
+							new TMethodEventJob<CXWindowsScreen>(this,
+								&CXWindowsScreen::handleSystemEvent));
 
 	// install the platform event queue
 	EVENTQUEUE->adoptBuffer(new CXWindowsEventQueueBuffer(m_display, m_window));