Installation failing with empty error message if password too short

Describe the bug

In the “Create your Super Admin account” step of Castopod installation, if the password is too small, it fails without giving any reason why.

Steps to reproduce

1. Deploy a fresh Castopod install (I did it with docker)
2. Go to http(s)://[localhost/your-domain]/cp-install
3. It will prompt for credentials to create a super admin account
4. Enter a correct username, email, and a short password (like pass)

Expected behavior

An error message stating that the password is too short should display.

Actual behavior

An empty error message box appears, leaving the user confused.

Relevant logs and/or screenshots

Context

• Castopod: 1.6.5
• OS: docker (host: archlinux)
• Browser: firefox & chrome
• Web server: nginx packaged in the castopod docker image