Don't notify users about relations that are not visible (#1005).

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/trunk@12015 e93f8b46-1217-0410-a6f0-8f06a7374b81
Use Hash#reject that returns a Hash with ruby1.8 when Hash#select that returns an Array.

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/trunk@12016 e93f8b46-1217-0410-a6f0-8f06a7374b81