Error on ActiveAdmin initializer

[fabrouy]

Hello!

When I add this:

config.before_action do
  left_sidebar! if respond_to?(:left_sidebar!)
end

to my AA initializer I get:

`load_missing_constant': Circular dependency detected while autoloading constant User (RuntimeError)

The stacktrace is confusing but the line where I added the new code is mentioned.

Tested with AA 1.0.0 and 1.1.0

Am I doing something wrong?