Check if WX recognized a key before testing if it's a hotkey

Fixes issue 5537.

Source/Core/DolphinWX/Src/Frame.cpp

@@ -797,8 +797,9 @@ void CFrame::OnGameListCtrl_ItemActivated(wxListEvent& WXUNUSED (event))
 
 bool IsHotkey(wxKeyEvent &event, int Id)
 {
-	return (event.GetKeyCode() == SConfig::GetInstance().m_LocalCoreStartupParameter.iHotkey[Id] &&
-			event.GetModifiers() == SConfig::GetInstance().m_LocalCoreStartupParameter.iHotkeyModifier[Id]);
+	return (event.GetKeyCode() &&
+	        event.GetKeyCode() == SConfig::GetInstance().m_LocalCoreStartupParameter.iHotkey[Id] &&
+	        event.GetModifiers() == SConfig::GetInstance().m_LocalCoreStartupParameter.iHotkeyModifier[Id]);
 }
 
 int GetCmdForHotkey(unsigned int key)