ppf: print url if fetching failed

ppf.py

@@ -43,7 +43,9 @@ def fetch_contents(url):
 	]
 	proxies = [rocksock.RocksockProxyFromURL('socks4://%s' % random.choice( config.torhosts ))]
 	http = RsHttp(host,ssl=ssl,port=port, keep_alive=True, timeout=15, max_tries=1, follow_redirects=True, auto_set_cookies=True, proxies=proxies, user_agent='Mozilla/5.0 (Windows NT 6.1; rv:60.0) Gecko/20100101 Firefox/60.0')
-	if not http.connect(): return ''
+	if not http.connect():
+		_log("failed to connect to %s"%url, "ppf")
+		return ''
 	hdr, res = http.get(uri, headers)
 	res = res.encode('utf-8') if isinstance(res, unicode) else res
 	for retry_message in retry_messages: