WordPress: Prevent Contact 7 javascript and stylesheets from loading on EVERY page

contact_7_prevent_loader.php

<?php  
/**
 * Prevent Contact Form 7 javascript and styles from loading on every page
 * Load them only on pages that contain the CF7 shortcode!
 * @author @david <david@davidvandenbor.nl>
 */

function david_dequeue_scripts() {
    $load_scripts = false;
    if( is_singular() ) {
    	$post = get_post();
    	if( has_shortcode($post->post_content, 'contact-form-7') ) {
        	$load_scripts = true;
    	}
    }
    if( ! $load_scripts ) {
        wp_dequeue_script( 'contact-form-7' );
        wp_dequeue_style( 'contact-form-7' );
    }
}
add_action( 'wp_enqueue_scripts', 'david_dequeue_scripts', 99 );