Prevent no page found for Skype call link

function ss_allow_skype_protocol( $protocols ){
$protocols[] = 'skype';
return $protocols;
}
add_filter( 'kses_allowed_protocols' , 'ss_allow_skype_protocol' );

Then add link as  

 <a href="skype:[skype_username]?call">Skype</a>

 in any template