Merged r11491 from trunk to 2.3-stable (#13310)

pt-BR "label_last_n_weeks" translation updated.

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/branches/2.3-stable@11493 e93f8b46-1217-0410-a6f0-8f06a7374b81