typo in porters handbook

[Dan Langille]

I was just reading:

http://www.freebsd.org/doc/en_US.ISO8859-1/books/porters-
handbook/makefile-categories.html#PORTING-CATEGORIES

(for extra credit, you can include the other files that have to 
changes, as per the procedure in the Committer's Guide.)

That should be change, not changes I think.

thanks
-- 
Dan Langille : http://www.langille.org/
BSDCan - The Technical BSD Conference - http://www.bsdcan.org/