App Passwords: Include authorization rewrite rule in default multisite .htaccess

This rule was previously added to `WP_Rewrite`, but multisite uses a different .htaccess generation mechanism.

Props pbiron.
Fixes #51772.
See [49109].

Built from https://develop.svn.wordpress.org/trunk@49607


git-svn-id: http://core.svn.wordpress.org/trunk@49345 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-admin/includes/network.php

@@ -640,6 +640,7 @@ define('BLOG_ID_CURRENT_SITE', 1);
 
 		$htaccess_file = <<<EOF
 RewriteEngine On
+RewriteRule .* - [E=HTTP_AUTHORIZATION:%{HTTP:Authorization}]
 RewriteBase {$base}
 RewriteRule ^index\.php$ - [L]
 {$ms_files_rewriting}

wp-includes/version.php

@@ -13,7 +13,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.6-beta4-49606';
+$wp_version = '5.6-beta4-49607';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.