[kemonoparty] warn about missing DDoS-GUARD cookies

gallery_dl/extractor/kemonoparty.py

@@ -22,8 +22,15 @@ class KemonopartyExtractor(Extractor):
     directory_fmt = ("{category}", "{service}", "{user}")
     filename_fmt = "{id}_{title}_{num:>02}_{filename}.{extension}"
     archive_fmt = "{service}_{user}_{id}_{num}"
+    cookiedomain = ".kemono.party"
+    _warning = True
 
     def items(self):
+        if self._warning:
+            if not self._check_cookies(("__ddg1", "__ddg2")):
+                self.log.warning("no DDoS-GUARD cookies set (__ddg1, __ddg2)")
+            KemonopartyExtractor._warning = False
+
         find_inline = re.compile(r'src="(/inline/[^"]+)').findall
 
         if self.config("metadata"):