Rails3: scm: git: use .to_s for overriding human_attribute_name parameter

On Rails 3.0.11, parameter is symbol not string in activerecord validation.

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/trunk@8975 e93f8b46-1217-0410-a6f0-8f06a7374b81

app/models/repository/git.rb

@@ -23,7 +23,7 @@ class Repository::Git < Repository
   validates_presence_of :url
 
   def self.human_attribute_name(attribute_key_name, *args)
-    attr_name = attribute_key_name
+    attr_name = attribute_key_name.to_s
     if attr_name == "url"
       attr_name = "path_to_repository"
     end