[Bug Report] Cannot authenticate via HTTP Basic Auth to access OPDS 

**Describe the bug**
See title.
**To Reproduce**
Steps to reproduce the behavior:
1. Run `curl "https://username:password@mango.supersonichub1.repl.co/opds"
2. See error

**Expected behavior**
I see my OPDS feed.

**Environment (please complete the following information):**
 - OS: Ubuntu 20.04.2
 - Mango Version: 0.27.0
