[bunkr] detect new maintenance video file (#8802)

* fix(bunkr): catch new maintenance video file during validation

Bunkr has performing a large scale maintenance recently, and I've
noticed that I would on occasion download a file only to get
a short server is in maintenance video instead of the intended file.

Debug logs show the filename for the maintenance video has changed:
[urllib3.connectionpool][debug] Starting new HTTPS connection (1): 3d09xl1.b-cdn.net:443
[urllib3.connectionpool][debug] https://3d09xl1.b-cdn.net:443 "GET /c4f36040-bdd1-40b6-aea1-034dfbe88ba2/maint.mp4 HTTP/1.1" 200 322509

This commit fixes the detection of that file to properly send the
"File server in maintenance mode" warning instead of downloading an
unintended file.

Signed-off-by: Benjamin VERGNAUD <ben@bvergnaud.fr>

* check multiple suffixes with one 'endswith()' call

---------

Signed-off-by: Benjamin VERGNAUD <ben@bvergnaud.fr>

gallery_dl/extractor/bunkr.py

@@ -202,7 +202,8 @@ class BunkrAlbumExtractor(LolisafeAlbumExtractor):
         }
 
     def _validate(self, response):
-        if response.history and response.url.endswith("/maintenance-vid.mp4"):
+        if response.history and response.url.endswith(
+                ("/maint.mp4", "/maintenance-vid.mp4")):
             self.log.warning("File server in maintenance mode")
             return False
         return True