Docs: Add a missing file header for wp-includes/class-wp-http-curl.php, introduced in [33748].

Also clarifies the class DocBlock summary for `WP_Http_Curl` to better describe its purpose.

See #33413. See #33701.


git-svn-id: https://develop.svn.wordpress.org/trunk@33874 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/class-wp-http-curl.php

@@ -1,11 +1,19 @@
 <?php
 /**
+ * HTTP API: WP_Http_Curl object class
+ *
+ * @package WordPress
+ * @subpackage HTTP
+ * @since 4.4.0
+ */
+
+/**
+ * Core class used to integrate Curl as an HTTP transport.
+ *
  * HTTP request method uses Curl extension to retrieve the url.
  *
  * Requires the Curl extension to be installed.
  *
- * @package WordPress
- * @subpackage HTTP
  * @since 2.7.0
  */
 class WP_Http_Curl {