```
pt_BR.ISO8859-1/books/porters-handbook: Sync with en_US r53525
Also fix some failing strings (Weblate warnings).
Approved by: ???
Obtained from: https://weblate.eastus.cloudapp.azure.com/projects/freebsd-doc/boooks_porters-handbook/pt_BR/
Differential Revision: https://reviews.freebsd.org/D22270
```