change results of text.nameext_from_url()

Instead of getting a complete 'filename' from an URL and splitting that
into 'name' and 'extension', the new approach gets rid of the complete
version and renames 'name' to 'filename'. (Using anything other than
{extension} for a filename extension doesn't really work anyway)

Example: "https://example.org/path/filename.ext"

before:
- filename : filename.ext
- name     : filename
- extension: ext

now:
- filename : filename
- extension: ext

gallery_dl/extractor/khinsider.py

@@ -17,7 +17,7 @@ class KhinsiderSoundtrackExtractor(AsynchronousMixin, Extractor):
     category = "khinsider"
     subcategory = "soundtrack"
     directory_fmt = ("{category}", "{album}")
-    archive_fmt = "{album}_{name}.{extension}"
+    archive_fmt = "{album}_{filename}.{extension}"
     pattern = (r"(?:https?://)?downloads\.khinsider\.com"
                r"/game-soundtracks/album/([^/?&#]+)")
     test = (("https://downloads.khinsider.com"
@@ -25,7 +25,7 @@ class KhinsiderSoundtrackExtractor(AsynchronousMixin, Extractor):
         "pattern": r"https?://\d+\.\d+\.\d+\.\d+/ost/horizon-riders-wii/[^/]+"
                    r"/Horizon%20Riders%20Wii%20-%20Full%20Soundtrack\.mp3",
         "count": 1,
-        "keyword": "d91cf3edee6713b536eaf3995743f0be7dc72f68",
+        "keyword": "b4f460c78dd23e1f1121f4ac784dd67ded7c2679",
     })
     root = "https://downloads.khinsider.com"