Allow lernid to accept custom classroom channels

The #ubuntu-classroom-es channel is a low traffic classroom where people interpret in real time the sessions done in #ubuntu-classroom. This is different from #ubuntu-charlas because this last channel have its own calendar with its own hispanic speakers too.

We cannot recommend lernid because people interested in following both, the #ubuntu-classroom and the #ubuntu-classroom-es for the interpretation can not enter to the last one.

My coding skills are pretty limited, however if no one is interested I'd like to change it myself