Fix typo in NodeJS Cheat Sheet

[notsoshant]

Fix a typo in X-Frame-Options helmet code

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[ThunderSon]

Thanks for spotting that!

[ThunderSon]

Would you be able to resolve the conflicts? It's the file name that changed. Let me know if you need help :)

[notsoshant]

Resolved the conflict. Please check.

[rbsec]

Looks good, thanks.