Consolidating racks violates the RF contract

I have only tested this on 2.0 so far, but I suspect it will affect multiple versions.

Repro:

• create a datacenter with rf>1
• create more than one rack in this datacenter
• consolidate these racks into 1
• getendpoints will reveal the RF in practice is 1, even though other tools will report the original RF that was set

Restarting Cassandra will resolve this.