[chevereto] fix 'id' for links without file name (#8307)

e.g. https://jpg6.su/img/LecXGS/

gallery_dl/extractor/chevereto.py

@@ -75,7 +75,7 @@ class CheveretoImageExtractor(CheveretoExtractor):
                     fromhex=True)
 
         file = {
-            "id"   : self.path.rpartition(".")[2],
+            "id"   : self.path.rpartition("/")[2].rpartition(".")[2],
             "url"  : url,
             "album": text.remove_html(extr(
                 "Added to <a", "</a>").rpartition(">")[2]),

test/results/jpgfish.py

@@ -24,6 +24,23 @@ __tests__ = (
     "user"     : "exearco",
 },
 
+{
+    "#url"     : "https://jpg6.su/img/LecXGS/",
+    "#comment" : "image ID without name (#8307)",
+    "#category": ("chevereto", "jpgfish", "image"),
+    "#class"   : chevereto.CheveretoImageExtractor,
+    "#results"     : "https://simp3.jpg5.su/images/funnymeme.jpg",
+    "#sha1_content": "098e5e9b17ad634358426e0ffd1c93871474d13c",
+
+    "album"    : "",
+    "date"     : "dt:2022-06-05 03:24:25",
+    "extension": "jpg",
+    "filename" : "funnymeme",
+    "id"       : "LecXGS",
+    "url"      : "https://simp3.jpg5.su/images/funnymeme.jpg",
+    "user"     : "exearco",
+},
+
 {
     "#url"     : "https://jpg.church/img/auCruA",
     "#category": ("chevereto", "jpgfish", "image"),