Yes, indeed I can show website over https with WebEngine, even though it still show those warning messages. As documented here, Web Kit will be deprecated in Qt version 5.5+, so I'll switch to use WebEngine then.
For those who feel annoyed with the warning messages, you could suppress them by calling following method in your main()
@SGaist Thank you for the reply. But I am a newbie here and don't know anything. So can you please send me download link for whichever of "Visual Studio 2013" and "Qt's MinGW version" is a smaller file to download.
Or is there any other way so that I need to download minimum data.