Crashes when CONSUL_ADDR or NOMAD_ADDR is invalid

[thnee]

Tested with v0.20.1 dockerhub image, frontend crashes when backend has these addresses misconfigured.

When NOMAD_ADDR is invalid (e.g. http://invalid:4646).

Returned frame when fetching regions:

{"Type":"NOMAD_FETCHED_REGIONS","Index":0,"Payload":null}

Crash in console:

main.fc4fd4a5ae2d152e140c.js:1 uncaught at read TypeError: Cannot convert undefined or null to object
    at keys (<anonymous>)
    at SelectNomadRegion.value (http://hashiui.example.com/static/main.fc4fd4a5ae2d152e140c.js:1:2104743)
    at l._renderValidatedComponentWithoutOwnerOrContext (http://hashiui.example.com/static/main.fc4fd4a5ae2d152e140c.js:1:1196704)
    at l._renderValidatedComponent (http://hashiui.example.com/static/main.fc4fd4a5ae2d152e140c.js:1:1196831)
    at l._updateRenderedComponent (http://hashiui.example.com/static/main.fc4fd4a5ae2d152e140c.js:1:1196135)
    at l._performComponentUpdate (http://hashiui.example.com/static/main.fc4fd4a5ae2d152e140c.js:1:1195936)
    at l.updateComponent (http://hashiui.example.com/static/main.fc4fd4a5ae2d152e140c.js:1:1195214)
    at l.receiveComponent (http://hashiui.example.com/static/main.fc4fd4a5ae2d152e140c.js:1:1194331)
    at Object.receiveComponent (http://hashiui.example.com/static/main.fc4fd4a5ae2d152e140c.js:1:141141)
    at l._updateRenderedComponent (http://hashiui.example.com/static/main.fc4fd4a5ae2d152e140c.js:1:1196179)

When CONSUL_ADDR is invalid (e.g. invalid:8500).

Returned frame when fetching regions:

{"Type":"CONSUL_FETCHED_REGIONS","Index":0,"Payload":null}

Crash in console:

main.fc4fd4a5ae2d152e140c.js:1 uncaught at read TypeError: Cannot convert undefined or null to object
    at keys (<anonymous>)
    at SelectConsulRegion.value (http://hashiui.example.com/static/main.fc4fd4a5ae2d152e140c.js:1:2134379)
    at l._renderValidatedComponentWithoutOwnerOrContext (http://hashiui.example.com/static/main.fc4fd4a5ae2d152e140c.js:1:1196704)
    at l._renderValidatedComponent (http://hashiui.example.com/static/main.fc4fd4a5ae2d152e140c.js:1:1196831)
    at l._updateRenderedComponent (http://hashiui.example.com/static/main.fc4fd4a5ae2d152e140c.js:1:1196135)
    at l._performComponentUpdate (http://hashiui.example.com/static/main.fc4fd4a5ae2d152e140c.js:1:1195936)
    at l.updateComponent (http://hashiui.example.com/static/main.fc4fd4a5ae2d152e140c.js:1:1195214)
    at l.receiveComponent (http://hashiui.example.com/static/main.fc4fd4a5ae2d152e140c.js:1:1194331)
    at Object.receiveComponent (http://hashiui.example.com/static/main.fc4fd4a5ae2d152e140c.js:1:141141)
    at l._updateRenderedComponent (http://hashiui.example.com/static/main.fc4fd4a5ae2d152e140c.js:1:1196179)