Tight loop in vxlan manager causes high CPU usage
Tight loop in vxlan manager causes high CPU usage

Problem:
High CPU usage when controller should be idling with no orchestration
changes

Solution:
The vxlan manager consumer should not use a default select case for the
channel read. This allows the process to tight loop when no reads are
available. It is OK to block on this read.

Fixes #555

sjberman/k8s-bigip-ctlr,sjberman/k8s-bigip-ctlr,michaeldayreads/k8s-bigip-ctlr,sjberman/k8s-bigip-ctlr,michaeldayreads/k8s-bigip-ctlr,sjberman/k8s-bigip-ctlr,F5Networks/k8s-bigip-ctlr,michaeldayreads/k8s-bigip-ctlr,F5Networks/k8s-bigip-ctlr,sjberman/k8s-bigip-ctlr,F5Networks/k8s-bigip-ctlr,F5Networks/k8s-bigip-ctlr,michaeldayreads/k8s-bigip-ctlr,michaeldayreads/k8s-bigip-ctlr