Fix about_to_str koan

[#54145709]
Revert "Update about_to_str.rb"

This reverts commit e5189d3b41f47b7c586de71384cb9228c03ce5fa.
Merge pull request #31 from bayendor/54145709_about_to_str_master

Fix about_to_str koan

[Delivers #54145709]