[Infra UI] Nginx metrics are not displayed on matching nodes with Nginx data

[simianhacker]

Kibana version: 6.6.0

Elasticsearch version: 6.6.0

Server OS version: all

Browser version: all

Browser OS version: all

Original install method (e.g. download page, yum, from source, etc.): bc

Describe the bug:

Nginx section should show up if the Nginx data is available for a node.

Steps to reproduce:

1. Send Nginx data to Elasticsearch for a host
2. Visit metrics page for host
3. Notice there is no Nginx metrics

Expected behavior:

There should be Nginx metrics for hosts that have Nginx data.

[elasticmachine]

Pinging @elastic/infrastructure-ui

[simianhacker]

Looks like there is a typo in the Nginx layout definition.