Merge pull request #358 from keesschepers/develop

Make it possible to bypass proxy.

library/Solarium/Core/Client/Adapter/Curl.php

@@ -122,7 +122,7 @@ class Curl extends Configurable implements AdapterInterface
         curl_setopt($handler, CURLOPT_TIMEOUT, $options['timeout']);
         curl_setopt($handler, CURLOPT_CONNECTTIMEOUT, $options['timeout']);
 
-        if ($proxy = $this->getOption('proxy')) {
+        if (null !== ($proxy = $this->getOption('proxy'))) {
             curl_setopt($handler, CURLOPT_PROXY, $proxy);
         }