Fix PlenaryCollection.set_logger()
Fix PlenaryCollection.set_logger()

We need to set our own logger too, in addition to updating the members.

Change-Id: I414413931c7def0ae096b4249c8a9114121ff47f
Reviewed-by: Priya Joshi <3c6cfa6f57440adfc837c4ad04483313acbc2582@morganstanley.com>

guillaume-philippon/aquilon,guillaume-philippon/aquilon,quattor/aquilon,quattor/aquilon,guillaume-philippon/aquilon,quattor/aquilon