title: Update not working in specific situation
body: <p>I am fetching a list of favourite skills for a user.<br>
  (userTable)->(user)->(favourite_skill)->(skills) </p>
  
  <pre><code>gun.get('userTable')
     .get(user.pk)
     .get('favorite_skill')
     .map()
     .on(
       (skill, pk) =&gt; {
         cb(skill, pk)
       }
     )
  </code></pre>
  
  <p>After editing one of those skills and updating, nothing happens.
  The data remains the same on the gun server as well.</p>
  
  <pre><code>gun.get('skillTable').get(skill.pk).put(skill)
  </code></pre>
  
  <p>All works well when I fetch a complete skill list like this:</p>
  
  <pre><code>gun.get('skillTable').map().on(....)
  </code></pre>