Early exit when maintenance mode is enabled and users have the permission to access the site in maintenance mode, or when the redirect URL has not been set

The last steps the code takes before redirecting users is checking whether maintenance mode is enabled, the logged in user has the permission to access the site in maintenance mode, and the redirect URL has been set.

The code should instead:

• If the redirect URL has not been set, exit immediately
• If maintenance mode is enabled and the logged in user has the access site in maintenance mode permission, exit immediately

Then, the code should verify the other conditions are met.