Fix repr of "Attribute" to look like before

[jensens]

and as usual in Python.

It broke tons of tests in Plone and related. Also the repr looks like it's usual in Python.

[jamadden]

Whoops, left out the 'object'. Thanks.

Maybe the change note could be a bit more descriptive? I was afraid everything helpful about the repr changes had been reverted.

Actually, maybe it doesn't even need a change note, since it's a slight tweak to a change introduced for this same release (that's not yet published).

[jensens]

indeed, I'll remove the note at all, as it is a fix for the newly introduced change.