fix moving files from external storage to object store trashbin

having the "cache rename" after the "storage move" caused the target
to get the fileid from the source file, without taking care that the object
is stored under the original file id.

By doing the "cache rename" first, we trigger the "update existing file"
logic while moving the file to the object store and the object gets stored for the
correct file id

Signed-off-by: Robin Appelman <robin@icewind.nl>