Redirect URI without trailing slash to fix broken HTML assets

[geftactics]

Original code has a slight issue that causes HTML assets to not load correctly.

Example: http://domain/subdir

• The function modifies the request to fetch http://domain/subdir/index.html
• The index.html refers to assets such as <img src='image.png />
• Browser attempts to fetch from http://domain/image.png rather than http://domain/subdir/image.png

By modifying the else if statement to perform a 302 redirect, and append a trailing slash, the next time our CloudWatch function is called, it will be handled by the first if statement, with the browser requesting HTML assets from the correct location, as the base url now has the trailing slash in place.