Do not delete effects pointer from KWin::Application dtor

Not needed as the Compositor already deletes the effects pointer.

main.cpp

@@ -298,7 +298,6 @@ Application::~Application()
     if (owner.ownerWindow() != None)   // If there was no --replace (no new WM)
         XSetInputFocus(display(), PointerRoot, RevertToPointerRoot, xTime());
     delete options;
-    delete effects;
     delete atoms;
 }