XML-RPC: Re-add a `global $wpdb` missed in [38768].

See #37699.


Built from https://develop.svn.wordpress.org/trunk@38775


git-svn-id: http://core.svn.wordpress.org/trunk@38718 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/class-wp-xmlrpc-server.php

@@ -6210,6 +6210,8 @@ class wp_xmlrpc_server extends IXR_Server {
 	 * @return string|IXR_Error
 	 */
 	public function pingback_ping( $args ) {
+		global $wpdb;
+
 		/** This action is documented in wp-includes/class-wp-xmlrpc-server.php */
 		do_action( 'xmlrpc_call', 'pingback.ping' );
 

wp-includes/version.php

@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.7-alpha-38774';
+$wp_version = '4.7-alpha-38775';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.