Open redirect endpoint in Datasette

### Impact Deployed instances of Datasette prior to `0.65.2` and `1.0a21` include an open redirect vulnerability. Hits to the path `//example.com/foo/bar/` (the trailing slash is required) will redirect the user to `https://example.com/foo/bar`. ### Patches This problem has been patched in both Datasette `0.65.2` and `1.0a21`. ### Workarounds If Datasette is running behind a proxy that proxy could be configured to replace `//` with `/` in incoming request URLs.