Install redirect

[lukeyouell]

Description

Small one...

When transferring a project to staging if you visit the CP before connecting to the DB you see the install page as expected, after connecting the DB and refreshing the page you're taken to the login page (again, as expected) but upon logging in you're taken back to the install page which throws a 404.

I know this is the expected behaviour but I think it would be better to redirect the user to the CP dashboard, possibly displaying a notice stating "Craft already installed" or something.

Additional info

• Craft version: 3.0.16.1