WX: Replace SetIcon with SetIcons(wxIconBundle)

Setting a single icon at a single resolution doesn't scale well,
Windows requires a 16x16 icon for the window and a 32x32/48x48 for
the taskbar. Providing all icons produces less pixellated results at
HiDPI.

Source/Core/DolphinWX/NetPlay/NetWindow.cpp

@@ -70,6 +70,7 @@ NetPlayDialog::NetPlayDialog(wxWindow* const parent, const CGameListCtrl* const
 {
   Bind(wxEVT_THREAD, &NetPlayDialog::OnThread, this);
   CreateGUI();
+  SetIcons(WxUtils::GetDolphinIconBundle());
   Center();
 
   // Remember the window size and position for NetWindow