[hitomi] fix image URLs and URL pattern

- non-webp files are now hosted on [a-c]b.hitomi.la
- removed ampersand from invalid slug characters

gallery_dl/extractor/hitomi.py

@@ -21,10 +21,10 @@ class HitomiGalleryExtractor(GalleryExtractor):
     root = "https://hitomi.la"
     pattern = (r"(?:https?://)?hitomi\.la"
                r"/(?:manga|doujinshi|cg|gamecg|galleries|reader)"
-               r"/(?:[^/?&#]+-)?(\d+)")
+               r"/(?:[^/?#]+-)?(\d+)")
     test = (
         ("https://hitomi.la/galleries/867789.html", {
-            "pattern": r"https://[a-c]a.hitomi.la/images/./../[0-9a-f]+.jpg",
+            "pattern": r"https://[a-c]b.hitomi.la/images/./../[0-9a-f]+.jpg",
             "keyword": "4873ef9a523621fc857b114e0b2820ba4066e9ae",
             "count": 16,
         }),
@@ -35,12 +35,12 @@ class HitomiGalleryExtractor(GalleryExtractor):
         }),
         # Game CG with scenes (#321)
         ("https://hitomi.la/galleries/733697.html", {
-            "url": "b4cbc76032852db4a655bf6a2c4d58eae8153c8e",
+            "url": "ec3fe9b708ee376ec579b90d053ad485c0777552",
             "count": 210,
         }),
         # fallback for galleries only available through /reader/ URLs
         ("https://hitomi.la/galleries/1045954.html", {
-            "url": "f3aa914ad148437f72d307268fa0d250eabe8dab",
+            "url": "bf4ed4e726204da5bc37a236ca476a2a96081388",
             "count": 1413,
         }),
         # gallery with "broken" redirect
@@ -143,7 +143,7 @@ class HitomiGalleryExtractor(GalleryExtractor):
             frontends = 2 if inum < 0x30 else 3
             inum = 1 if inum < 0x09 else inum
 
-            url = "https://{}a.hitomi.la/images/{}/{}/{}.{}".format(
+            url = "https://{}b.hitomi.la/images/{}/{}/{}.{}".format(
                 chr(97 + (inum % frontends)),
                 ihash[-1], ihash[-3:-1], ihash,
                 idata["extension"],