* fix(books): restore UNAM url

UNAM `https` link must be preserved. It is the author site.

https://lya.fciencias.unam.mx/jloa/publicaciones/analisisdeAlgoritmos.pdf

openlibra site is down (see #5470)

Resolves EbookFoundation/free-programming-books#6224
Fixes EbookFoundation/free-programming-books#5916 
Fixes EbookFoundation/free-programming-books#6097

* chore(books): set author

BOOK:        Breves Notas sobre Análisis de Algoritmos
AUTHOR:  Jorge L. Ortega Arjona
EDITOR:     Departamento de Matemáticas, Faultad de CienIas, UNAM (Universidad Nacional Autónoma de México)
DATE:       marzo 2005