Navigation contents disappears when upgrading to 2.3.73 #1774

Describe the bug
After upgrading from 2.2.51 to 2.3.73, custom navigation menu contents disappear.

To Reproduce
Steps to reproduce the behavior:

1. Set a custom navigation menu.
2. Upgrade wiki.js to 2.3.73.
3. See the navigation menu or 'navigation' tab in the administration screen.

Expected behavior
Hold the whole contents after the upgrade.

Screenshots

Host Info (please complete the following information):

• OS: Docker Container (Linux)
• Wiki.js version: 2.3.73
• Database engine: postgres 11.6

Additional context