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/ngomik.py

@@ -20,7 +20,7 @@ class NgomikChapterExtractor(ChapterExtractor):
                r"(/[^/?&#]+-chapter-[^/?&#]+)")
     test = ("https://www.ngomik.in/14-sai-no-koi-chapter-1-6/", {
         "url": "8e67fdf751bbc79bc6f4dead7675008ddb8e32a4",
-        "keyword": "7cc913ed2b9018afbd3336755d28b8252d83044c",
+        "keyword": "204d177f09d438fd50c9c28d98c73289194640d8",
     })
 
     def metadata(self, page):