Backward compatibility

[openhood]

Please replace line 99 of search.rb
scope = conditions.inject(klass.scoped(current_scope)) do |scope, condition|
with
scope = conditions.inject(klass.scoped(current_scope || {})) do |scope, condition|
otherwise it doesn't work with Rails 2.2.2

This issue was already described here http://binarylogic.lighthouseapp.com/projects/16601/tickets/94-nil-object-error but no solution has been given apart from upgrading to Rails 2.3.x, which sadly is often not possible.