update default return url

[tormodmacleod]

hello

this merge request may be misguided but i created issue #249 . i discovered that if i set

            "redirect_url": "http://localhost:8484"

in ~/.config/restish/apis.json i experience the issue but if i set

            "redirect_url": "http://localhost:8484/"

it works just fine. when i looked i discovered that this was changed in https://github.com/danielgtaylor/restish/commit/ac559b95dc5a4432103107ec621d2568f102499e and the trailing / was omitted. i'm assuming this was an error but if it's intentional please just disregard this merge request