Customize: Update the introduced version in the docs for the `get_header_video_url` filter to 4.7.3.

See #39512.

Built from https://develop.svn.wordpress.org/trunk@40086


git-svn-id: http://core.svn.wordpress.org/trunk@40023 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/theme.php

@@ -1346,7 +1346,7 @@ function get_header_video_url() {
 	/**
 	 * Filters the header video URL.
 	 *
-	 * @since 4.8.0
+	 * @since 4.7.3
 	 *
 	 * @param string $url Header video URL, if available.
 	 */

wp-includes/version.php

@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.8-alpha-40082';
+$wp_version = '4.8-alpha-40086';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.