Restore some more cap checks for clarity. See #15326.

git-svn-id: http://svn.automattic.com/wordpress/trunk@16776 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-admin/plugins.php

@@ -9,6 +9,9 @@
 /** WordPress Administration Bootstrap */
 require_once('./admin.php');
 
+if ( !current_user_can('activate_plugins') )
+	wp_die( __( 'You do not have sufficient permissions to manage plugins for this site.' ) );
+			
 $wp_list_table = get_list_table('WP_Plugins_List_Table');
 $wp_list_table->check_permissions();