android studio error Error:Connection timed out
<p>I just create a new Project in the android studio and add gcm module to it.<br>
and I keep giving this error message       </p>

<pre><code>Error:Connection timed out: connect. If you are behind an HTTP proxy, please configure the proxy settings either in IDE or Gradle.      
</code></pre>

<p>and I do not use any proxy.<br>
can anyone help me about this?</p>

<p><strong>Update</strong><br>
now after rebuild my project i give this error      </p>

<pre><code>Error:A problem occurred configuring project ':app'.    
 A problem occurred configuring project ':backend'.
Could not resolve all dependencies for configuration ':backend:classpath'.
   Could not resolve com.google.appengine:gradle-appengine-plugin:1.9.18.
    Required by:
        PushStart:backend:unspecified
      Could not resolve com.google.appengine:gradle-appengine-plugin:1.9.18.
      Could not get resource 'https://jcenter.bintray.com/com/google/appengine/gradle-appengine-plugin/1.9.18/gradle-appengine-plugin-1.9.18.pom'.
      Could not GET 'https://jcenter.bintray.com/com/google/appengine/gradle-appengine-plugin/1.9.18/gradle-appengine-plugin-1.9.18.pom'.
      Connection to https://jcenter.bintray.com refused
</code></pre>