BUG: Undue undeployed Pool removal

Undue **undeployed** _Pool_ removal at _VIP_ deletion.
The **undeployed** _Pools_ can't be removed at _VIP_ deletion if they are _simultaneously_ associated with another _VIP_. **Undeployed** _Pools_ removal at _VIP_ removal is expected only in the case of **the last association** with _VIPs_.