title: telegraf enum plugin not injecting the correct destination field
body: <p>I have the following telegraf configurations:</p>
  <pre><code>[[inputs.http_response]]
  name_override=&quot;test&quot;
  address=&quot;https://localhost:12345/test&quot;
  response_timeout=&quot;5s&quot;
  method=&quot;GET&quot;
  follow_redirects=false
  insecure_skip_verify = true
  response_string_match=&quot;test is up&quot;
   [inputs.http_response.tags]
      system=&quot;system&quot;
      component=&quot;component&quot;
  [[processors.enum]]
   [[processors.enum.mapping]]
      field = &quot;result_type&quot;
      dest = &quot;value&quot;
     [processors.enum.mapping.value_mappings]
       success = 1
  </code></pre>
  <p>And i get the following response:</p>
  <pre><code>test,component=component,system=system result_type=&quot;success&quot; 1611588662000000000
  </code></pre>
  <p>I was anticipating</p>
  <pre><code>test,component=component,system=system result_type=&quot;success&quot;,value=1i 1611588662000000000
  </code></pre>
  <p>What am i doing incorrectly here? I'm using version <code>1.9.2</code> and it shows it has the plugin.</p>