Make use of default category var

[joelanman]

Earlier in the code a default category is set if one is not sent:

 {%- set category -%}
    {%- if params.category -%}
      {{ params.category }}
    {%- else -%}
      analytics
    {%- endif -%}
  {%- endset -%}

However later on the code refers to params.category - which could be null. If it is null the javascript breaks. This PR refers to category instead to make sure a value is present.

[netlify]

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[owenatgov]

Makes perfect sense to me.

For some reason netlify failed to deploy this and is still recording the deploy preview a failure even though I re-ran it and it deployed fine. Something for a second reviewer to keep in mind.

[joelanman]

also I think the default code could be rewritten as either of these:

{% set category = params.category or "analytics" %}

{% set category = params.category | default "analytics" %}