Removing reference to disabled search service

While reviewing the translated version of this article (pt_BR) I saw that the Google service for specific BSD searches referenced in this article was disabled in 2011.

There is more details about this service being discontinued at:
https://www.freebsdnews.com/2011/06/08/google-discontinues-bsd-search-google-combsd/

Submitted by: ebrandi
Reviewed by: allanjude, eadler
Approved by: gabor
Differential Revision: https://reviews.freebsd.org/D16949