[nhentai] provide 'gallery_id' for pagination results (#7868)

gallery_dl/extractor/nhentai.py

@@ -88,6 +88,7 @@ class NhentaiExtractor(Extractor):
         data = {"_extractor": NhentaiGalleryExtractor}
         for gallery_id in self._pagination():
             url = f"{self.root}/g/{gallery_id}/"
+            data["gallery_id"] = text.parse_int(gallery_id)
             yield Message.Queue, url, data
 
     def _pagination(self):

test/results/nhentai.py

@@ -55,6 +55,8 @@ __tests__ = (
     "#pattern" : nhentai.NhentaiGalleryExtractor.pattern,
     "#range"   : "1-30",
     "#count"   : 30,
+
+    "gallery_id": int,
 },
 
 {