Bug: login form crashes on empty email field

[sanling1]

Description

When submitting the login form with an empty email field, the page crashes with a 500 error instead of showing a validation error.

Steps to Reproduce

1. Go to /login
2. Leave email field empty
3. Click submit

Expected Behavior

Should show "Email is required" validation error.

Environment

• Browser: Chrome 120
• OS: macOS 14.3