Css version number removal [duplicate]

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• How to remove file versions from the file source links in wp_head? 2 answers

How do I remove the version number from the CSS?

I have a childtheme of twentytwelve theme and the source code of the site includes this line

<link rel='stylesheet' id='twentytwelve-style-css'  
href='http://ift.tt/1GpvmnC'
type='text/css' media='all' />

I see in that in the functions of twentytwelve theme the 'twentytwelve_scripts_styles()" function contains thisL 'wp_enqueue_style( 'twentytwelve-style', get_stylesheet_uri() )" and I think that adds the version number. I cannot redefine the same function in the child theme. So how do I ensure that the css of the childtheme is pulled in without version number. Currently when I update my CSS, the changes don't show because of the "?ver=4.1.1" part.