title: ElasticsearchIllegalArgumentException: Illegal plugin name
body: <p>I am trying to use <a href="https://github.com/sscarduzio/elasticsearch-readonlyrest-plugin" rel="nofollow">https://github.com/sscarduzio/elasticsearch-readonlyrest-plugin</a></p>
  
  <p>My E.S version is 1.4.4 , and as soon as i run the first command  :</p>
  
  <pre><code>bin/plugin install https://github.com/sscarduzio/elasticsearch-readonlyrest-plugin/blob/master/download/elasticsearch-readonlyrest-v1.9.2_es-v2.3.2.zip?raw=true
  </code></pre>
  
  <p>I end up with :</p>
  
  <pre><code>Message:
     Error while installing plugin, reason: ElasticsearchIllegalArgumentException: Illegal plugin name: 
  </code></pre>