Remove query strings from static resources - Wordpress

this should do the job.. this removes the querystring on the frontend not the admin site.

Update: Add this into your functions.php file. Ensure that its kept within the PHP tags.

function rm_query_string( $src ){   
    $parts = explode( '?ver', $src );
    return $parts[0];
}

if ( !is_admin() ) {
    add_filter( 'script_loader_src', 'rm_query_string', 15, 1 );
    add_filter( 'style_loader_src', 'rm_query_string', 15, 1 );
}

This plugin will remove query strings from static resources like CSS & JS files, and will improve your speed scores in services like PageSpeed, YSlow, Pingdoom and GTmetrix.

Resources with a “?” or “&” in the URL are not cached by some proxy caching servers, and moving the query string and encode the parameters into the URL will increase your WordPress site performance significant.

// Remove Query String
function nerodev_remove_query_string($src) {
    $parts = explode('?ver=', $src);
    return $parts[0];
}
add_filter('script_loader_src', 'nerodev_remove_query_string', 15, 1);
add_filter('style_loader_src', 'nerodev_remove_query_string', 15, 1);

I found this here