_create_subcomponent: misleading error message

[danjampro]

The error message here: https://github.com/panoptes/POCS/blob/cf5ae075b9ad821d1215d1e6f1974caf131d3e1d/src/panoptes/pocs/camera/camera.py#L1048 is misleading because it states that the class is not callable. However, this error message also appears if an exception is raised while initialising a callable class.

[wtgee]

That's a bit odd as it's just catching a TypeError. I can add the error message in to see if that helps.