Merged r11791 from trunk to 2.3-stable (#13950)

remove duplicate Lithuanian "error_attachment_too_big" translation keys.

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/branches/2.3-stable@11792 e93f8b46-1217-0410-a6f0-8f06a7374b81