title: Graylog Search with Regex
body: <p>In my graylog Server, I want to create a search-value which finds the folowing query: <code>ctxt__Error:"User \"USERNAME\" not found."</code>.
  But I want to find ANY Error for every USERNAME. My Searchstring dowsnt work when I do this: <code>ctxt__Error:"User \"*\" not found."</code>
  Is there another way to do this?</p>