Fix crash when making code docs.
Fix crash when making code docs.

"make code-doc" was crashing due to a missing @class value.

R=matthew.scott, bac
CC=
https://codereview.appspot.com/9582044

bac/juju-gui,mitechie/juju-gui,jrwren/juju-gui,bac/juju-gui,jrwren/juju-gui,CanonicalJS/juju-gui,bac/juju-gui,jrwren/juju-gui,CanonicalJS/juju-gui,bac/juju-gui,CanonicalJS/juju-gui,jrwren/juju-gui,mitechie/juju-gui,mitechie/juju-gui,mitechie/juju-gui