Fix incorrect logs in network

These are negligible typo issues, so a bug isn't filed on LP.
We should log floating ip address and details of networks, rather than "|%s|"
or "|[<nova.db.sqlalchemy.models.Network object at 0x5227510>]|", so moving the
log of floating ip address to the correct location and converting the
sqlalchemy Network object to dict for logging.

Change-Id: I815bf01100d234401114bfd80fd9aa644d1a3447