fix(redirect): Use frontend_url for redirection

[jsayer101]

Hello,

I found that this redirect triggered when the account is already validated when trying to send a validation email doesn't follow the same behavior as the others (for exemple here and here)

An actual scenario that I came across :
I use it only with API, but my frontend follow redirects.
I ask for a validation email, I open it in a new tab. I close the tab where I'm now logged-in. I go back to the tab where I asked for the email. Clicking again on the "Send email" should redirect me to /dashboard (using my frontend), but it actually redirects me to /dashboard with the URL of my api.

What do you think ?

Thanks.

[taylorotwell]

Feel free to change in your own app.