DinghyBlonde on "config file has been changed"

A scan shows my config file was changed 9 hours ago. I have not been on the site and not sure what this means.

(unset( $line );
262 262
263 if ( ! is_writable(ABSPATH) ) : 263 if ( ! win_is_writable(ABSPATH) ) :
264 setup_config_display_header(); 264 setup_config_display_header(); )

I have the option to reset. is this safe and any insight into what changed this and what is means. I'm a noobie but working on eventually being in the codex.

Thanks for your help.