[trainline] set cookie _abck

in a local environment we can go on the site, if we are in a prod environment we have a timed out.
it's a blocking solution "Akamai", the  cookie is not limited to a user, to solve this we set up the _abck cookie to avoid the timed out,
by against the cookie may change over time, but as it is before going to the site i have no way to find the cookie