Fix incorrect rating for network.floating
Fix incorrect rating for network.floating

The volume of floating.ip pushed by ceilometer (whatever backend
used) is the numerical status of the floating, leading to an
incorrect rating by CK.

With ceilometer collector, the value is already forced to 1 (as
for compute). This patch fixes the bug for the gnocchi collector.

Change-Id: I974db35a87c3a791f25e19dbbeac77a4fae0a25f
Closes-Bug: #1659491

stackforge/cloudkitty,openstack/cloudkitty,openstack/cloudkitty,stackforge/cloudkitty