Parse configuration file for ERB (#16878).

Patch by Gavin Dunne.

git-svn-id: http://svn.redmine.org/redmine/trunk@13150 e93f8b46-1217-0410-a6f0-8f06a7374b81

lib/redmine/configuration.rb

@@ -82,7 +82,7 @@ module Redmine
       def load_from_yaml(filename, env)
         yaml = nil
         begin
-          yaml = YAML::load_file(filename)
+          yaml = YAML::load(ERB.new(File.read(filename)).result)
         rescue ArgumentError
           $stderr.puts "Your Redmine configuration file located at #{filename} is not a valid YAML file and could not be loaded."
           exit 1