Recreate nw_info after auto assigning floating ip.

When auto assigning floating IPs recreate the nw_info array
so that API calls to get instance details will immediately
display the assigned floating IP info.

Fixes LP Bug #1053479.

Change-Id: Ia58a5391099317479d968fcf01682229926a4a99
(cherry picked from commit ff8e3ef)

nova/network/manager.py

@@ -334,6 +334,10 @@ def allocate_for_instance(self, context, **kwargs):
                                        floating_address,
                                        fixed_address,
                                        affect_auto_assigned=True)
+
+            # create a fresh set of network info that contains the floating ip
+            nw_info = self.get_instance_nw_info(context, **kwargs)
+
         return nw_info
 
     @wrap_check_policy