Fix the /about route

[msm-code]

Your checklist for this pull request

• I've read the contributing guideline.
• I've tested my changes by building and running mquery, and testing changed functionality (if applicable)
• I've added automated tests for my change (if applicable, optional)
• I've updated documentation to reflect my change (if applicable)

What is the current behaviour?
Users can't visit /about route directly. It's handled by react on the client side, but server responds 404 to it. We already made this mistake before.

What is the new behaviour?
going to /about route directly works

Test plan
Visit /about.

Closing issues