No option to set load balancer status automatic

## Expected Behavior

It is good to have an option to force load balancer status of a node, and later reset to automatic status.

## Current Behavior

After forcing load balancer status to "alive" or "dead" on the nodes page, there is no option to return to automatic load balancer status.

## Possible Solution

The force load balancer status menu could be renamed to "set load balancer status" and the options would be "force dead", "force alive", "automatic"

## Steps to Reproduce (for bugs)

1. go to system/nodes
2. set load balancer status of a node to "dead"
3. try to set loadbalancer status back to automatic

## Context

## Your Environment

* Graylog Version: 2.4.3
* Elasticsearch Version: 5.6.9
* MongoDB Version: 3.4
* Operating System: Centos 7
* Browser version: any