Revert "show existing attachments when attachments are disabled"

putting this on a different branch so it doesn't conflict with my
pull request for the minimal theme.

This reverts commit 00a4eae.

includes/templates/docs/single/index.php

@@ -28,7 +28,7 @@
 
 	<?php do_action( 'bp_docs_after_doc_content' ) ?>
 
-	<?php if ( bp_docs_doc_has_attachments() ) : ?>
+	<?php if ( bp_docs_enable_attachments() && bp_docs_doc_has_attachments() ) : ?>
 		<div class="doc-attachments">
 			<h3><?php _e( 'Attachments', 'bp-docs' ) ?></h3>
 			<?php include ( bp_docs_locate_template( 'single/attachments.php' ) ) ?>