Fix Cannot convert object to primitive value

[benjie]

If root is created from Object.create(null) then String(root) throws Cannot convert object to primitive value which results in the confusing error Failed prop type: Cannot convert object to primitive value instead of the expected error Failed prop type: currentUser missing on {}

Checklist:

• If this PR is a new feature, please reference an issue where a consensus about the design was reached (not necessary for small changes)
• Make sure all of the significant new logic is covered by tests
• If this was a change that affects the external API used in GitHunt-React, update GitHunt-React and post a link to the PR in the discussion.

[apollo-cla]

	Fails
🚫	No CHANGELOG added.

	Warnings
⚠️	There are library changes, but not tests. That's OK as long as you're refactoring existing code

Generated by 🚫 dangerJS

[hwillson]

Great point - thanks @benjie!