While porting this module to make use of `pyone` I have overlooked one
attribute. Luckily the error only occurs when trying to rename an image
to a name that has already been taken.
Instead of telling the user which image ID already uses that name, the
module failed with the following error (along with a huge backtrace):
AttributeError: 'IMAGESub' object has no attribute 'id'
With this commit the error message is much more obvous again.
(cherry picked from commit b429c520f5)
Co-authored-by: Georg Gadinger <nilsding@nilsding.org>
