Fix typo in import of ChannelStore and use returnValue() instead of return inside active_channels (since it's a calls_manager method).
Fix typo in import of ChannelStore and use returnValue() instead of return inside active_channels (since it's a calls_manager method).

praekelt/vumi-go,praekelt/vumi-go,praekelt/vumi-go,praekelt/vumi-go