[redgifs] match gfycat image URLs (#4558)

gallery_dl/extractor/redgifs.py

@@ -177,6 +177,7 @@ class RedgifsImageExtractor(RedgifsExtractor):
     subcategory = "image"
     pattern = (r"(?:https?://)?(?:"
                r"(?:\w+\.)?redgifs\.com/(?:watch|ifr)|"
+               r"(?:\w+\.)?gfycat\.com(?:/gifs/detail|/\w+)?|"
                r"(?:www\.)?gifdeliverynetwork\.com|"
                r"i\.redgifs\.com/i)/([A-Za-z]+)")
     example = "https://redgifs.com/watch/ID"

test/results/redgifs.py

@@ -149,4 +149,10 @@ __tests__ = (
     "#class"   : redgifs.RedgifsImageExtractor,
 },
 
+{
+    "#url"     : "https://www.gfycat.com/foolishforkedabyssiniancat",
+    "#category": ("", "redgifs", "image"),
+    "#class"   : redgifs.RedgifsImageExtractor,
+},
+
 )