Replace more custom button classes with Bootstrap counterparts

templates/PhotoPage.php

@@ -242,7 +242,7 @@ class PhotoPage extends Template
 		echo '
 				<div id=user_actions_box>
 					<h3>Actions</h3>
-					<a class="btn btn-red" href="', BASEURL, '/', $this->photo->getSlug(), '?confirm_delete">Delete</a>
+					<a class="btn btn-danger" href="', BASEURL, '/', $this->photo->getSlug(), '?confirm_delete">Delete</a>
 				</div>';
 	}
 }