There's a logic bug in the destroy action: ip_flag is assuming string
context when it should be assuming list context. This causes ip_flag to
never get set to true and therefore floating IP's never get destroyed.
This can lead to floating IP exhaustion, particularly in environments
with a low number of allocatable floating IP's.
This patch corrects the problem by fixing the logic to check for a list
length of zero rather than an empty string.
Change-Id: I0205ac406e604365560360fc2953a5e90e1c9be3
Depends-On: Ifa9eeb9d761d9801cab580445e6c43c8cf1dfdaa
36900e12cd