Japanese translation updated by Go MAEDA (#18260)

git-svn-id: http://svn.redmine.org/redmine/trunk@13546 e93f8b46-1217-0410-a6f0-8f06a7374b81
Japanese translation changed (fix terms mismatch "default") by Go MAEDA (#18261)

git-svn-id: http://svn.redmine.org/redmine/trunk@13547 e93f8b46-1217-0410-a6f0-8f06a7374b81