scm: replace RAILS_DEFAULT_LOGGER to Rails.logger at abstract adapter.

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/trunk@6122 e93f8b46-1217-0410-a6f0-8f06a7374b81

lib/redmine/scm/adapters/abstract_adapter.rb

@@ -203,7 +203,7 @@ module Redmine
         end
 
         def self.logger
-          RAILS_DEFAULT_LOGGER
+          Rails.logger
         end
 
         def self.shellout(cmd, &block)