self-redirect check: run redirect check if status code is blank or do…

…es not start with 2, 4, 5,

to more aggressively check invalid status codes, should fix ukwa/ukwa-pywb#21

pywb/warcserver/resource/responseloader.py

@@ -195,8 +195,10 @@ def local_index_query(local_params):
         http_headers_buff = None
         if payload.rec_type in ('response', 'revisit'):
             status = cdx.get('status')
-            # status may not be set for 'revisit'
-            if not status or status.startswith('3'):
+
+            # if status is not set and not, 2xx, 4xx, 5xx
+            # go through self-redirect check just in case
+            if not status or not status.startswith(('2', '4', '5')):
                 http_headers = self.headers_parser.parse(payload.raw_stream)
                 self.raise_on_self_redirect(params, cdx,
                                             http_headers.get_statuscode(),