[SakugabooruBridge] Remove bridge

The target server for this bridge is no longer reachable and
there doesn't seem to be any attempt to get it back online.

bridges/SakugabooruBridge.php

@@ -1,11 +0,0 @@
-<?php
-require_once('MoebooruBridge.php');
-
-class SakugabooruBridge extends MoebooruBridge {
-
-	const MAINTAINER = 'mitsukarenai';
-	const NAME = 'Sakugabooru';
-	const URI = 'http://sakuga.yshi.org/';
-	const DESCRIPTION = 'Returns images from given page';
-
-}