title: Onesignal sending a push notification with tag filter fails with "All included players are not subscribed"
body: <p>When i send a request to onesignal with the following curl: </p>
  
  <pre><code>curl -X POST \
    https://onesignal.com/api/v1/notifications \
    -H 'Authorization: Basic &lt;omitted&gt;' \
    -H 'Cache-Control: no-cache' \
    -H 'Content-Type: application/json' \
    -d '{
    "app_id": "&lt;omitted&gt;",
    "filters": [
      {"field": "tag", "key": "broodjes", "relation": "exists"}
    ],
    "contents": {"en": "English Message"}
  }'
  </code></pre>
  
  <p>I'm trying to send a notification to all subscribed users with the tag "Broodjes".
  Anywhere it says <code>omitted</code> I have omitted the value for obvious reasons.</p>
  
  <p>Here is the unexpected response I get:</p>
  
  <pre><code>{
      "id": "",
      "recipients": 0,
      "errors": [
          "All included players are not subscribed"
      ]
  }
  </code></pre>
  
  <p>And <a href="https://i.stack.imgur.com/PeeyG.png" rel="nofollow noreferrer">here</a> is an image of the users I'm trying to notify.</p>