All scms which support blame use identifier.
This commit remove the link of cvs blame revision.
Redmine can not handle cvs revision (e.g. 1.2) as changeset identifier.
git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/trunk@5403 e93f8b46-1217-0410-a6f0-8f06a7374b81