Fix database schema update introduced in [30121].

The index must be manually dropped before `dbDelta()` can add the new index
without throwing a notice.

Fixes #22023.
Built from https://develop.svn.wordpress.org/trunk@30134


git-svn-id: http://core.svn.wordpress.org/trunk@30134 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/version.php

@@ -4,14 +4,14 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.1-alpha-30133';
+$wp_version = '4.1-alpha-30134';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.
  *
  * @global int $wp_db_version
  */
-$wp_db_version = 30056;
+$wp_db_version = 30133;
 
 /**
  * Holds the TinyMCE version