opennebula: fix error message when renaming an image (#3626) (#3650)

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>

changelogs/fragments/3626-fix-one_image-error.yml

@@ -0,0 +1,2 @@
+bugfixes:
+  - one_image - fix error message when renaming an image (https://github.com/ansible-collections/community.general/pull/3626).

plugins/modules/cloud/opennebula/one_image.py

@@ -306,7 +306,7 @@ def rename_image(module, client, image, new_name):
 
     tmp_image = get_image_by_name(module, client, new_name)
     if tmp_image:
-        module.fail_json(msg="Name '" + new_name + "' is already taken by IMAGE with id=" + str(tmp_image.id))
+        module.fail_json(msg="Name '" + new_name + "' is already taken by IMAGE with id=" + str(tmp_image.ID))
 
     if not module.check_mode:
         client.image.rename(image.ID, new_name)