Fix call_user_func bug on debugHandler_

Reviewed By: lucas


git-svn-id: https://svn.apache.org/repos/asf/incubator/thrift/trunk@664905 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/lib/php/src/transport/TSocket.php b/lib/php/src/transport/TSocket.php
index c193305..c33a352 100644
--- a/lib/php/src/transport/TSocket.php
+++ b/lib/php/src/transport/TSocket.php
@@ -147,7 +147,7 @@
     if ($this->handle_ === FALSE) {
       $error = 'TSocket: Could not connect to '.$this->host_.':'.$this->port_;
       if ($this->debug_) {
-        $this->debugHandler_($error);
+        call_user_func($this->debugHandler_, $error);
       }
       throw new Exception($error);
     }