fix(guide): Change true and false to equal and not equal in ternary operator challenge

[thecodingaviator]

• I have read freeCodeCamp's contribution guidelines.
• My pull request has a descriptive title (not a vague title like Update index.md)
• My pull request targets the master branch of freeCodeCamp.
• None of my changes are plagiarized from another source without proper attribution.
• All the files I changed are in the same world language (for example: only English changes, or only Chinese changes, etc.)
• My changes do not use shortened URLs or affiliate links.

[RandellDawson]

Good catch!