Bug? Invalid html

Version 2.7.0

The problem: code is not valid.

https://validator.w3.org/ shows error:

Error: CSS: Parse Error.

At line 141, column 24

ype="text/css">0</style><link 

file: register-settings.php

Starting from line 36:

	if ( is_null( $default ) ) {
		$default = crp_get_default_option( $key );
	}

If custom_css has not been set, $default equals to 0 here. Offtopic: I don’t know what custom_css is about.

In line 51 $value becomes also 0.

And this 0 goes directly to the html code, which results in invalidness. In this case $value must be an empty string instaed of 0.

I fixed like this in functions.php of my theme:

// Fix bug in contextual related posts {
function ved_crp_get_option_custom_css($value){
    return (0 ===  $value ? "" : $value);
}

add_filter( 'crp_get_option_custom_css', 'ved_crp_get_option_custom_css' );
//} Fix bug in contextual related posts

Please, correct the code.