Cast base_url to string to avoid warning on PHP 8.1

[kdambekalns]

On PHP 8.1, when no base_url is set, a warning is triggered because rtrim() expects a string as first argument.

[stof]

you should use https://github.com/FriendsOfBehat/MinkExtension/ instead, which is the new host of a maintained MinkExtension (and where this is already solved)

[kdambekalns]

you should use https://github.com/FriendsOfBehat/MinkExtension/ instead

Which by now I have found and do use, indeed. Thanks.