title: Matomo Track event doesn't work when params contains uppercase letters
body: <p>I'm tracking some events from my website. I have a Motomo server with basic configurations, nothing complicated. I'm tracking the events using the javascript API (not the tag manager, I don't have anything in the tag manager, and is not going to be used to track events). I'm able to track without problems except for this case:</p>
  <p>this works:</p>
  <pre><code>_paq.push(['trackEvent', 'add', 'add employee']);
  </code></pre>
  <p>if I go to Matomo server webpage to the menu Behavior -&gt; Events -&gt; Events Categories I can see created the category 'add'</p>
  <p>this doesn't work:</p>
  <pre><code>_paq.push(['trackEvent', 'Add', 'Add Employee']);
  </code></pre>
  <p>Doesn't work means that if I go to Matomo server webpage to the menu Behavior -&gt; Events -&gt; Events Categories is not creating the category 'Add' instead creates a category '-'</p>
  <p>This happens every time that the track events category parameter or action parameter has an upper case letter.</p>
  <p>Can someone please help me?
  Thanks</p>