Fix imagefap extrcator

gallery_dl/extractor/imagefap.py

@@ -194,7 +194,7 @@ class ImagefapFolderExtractor(ImagefapExtractor):
             cnt = 0
 
             while True:
-                gid = extr('<a  href="/gallery/', '"')
+                gid = extr(' id="gid-', '"')
                 if not gid:
                     break
                 yield gid, extr("<b>", "<"), folder_name

test/results/imagefap.py

@@ -120,6 +120,16 @@ __tests__ = (
     "#sha1_url": "37822523e6e4a56feb9dea35653760c86b44ff89",
 },
 
+{
+    "#url"     : "https://www.imagefap.com/organizer/613950/Grace-Stout",
+    "#category": ("", "imagefap", "folder"),
+    "#class"   : imagefap.ImagefapFolderExtractor,
+    "#pattern" : imagefap.ImagefapGalleryExtractor.pattern,
+    "#count"   : 31,
+
+    "title": r"re:Grace Stout .+",
+},
+
 {
     "#url"     : "https://www.imagefap.com/usergallery.php?userid=1981976&folderid=409758",
     "#category": ("", "imagefap", "folder"),