Add new Redgifs subdomain

Seems there's a v3 subdomain now (looks like it's mostly for mobile)

bdfr/site_downloaders/download_factory.py

@@ -28,7 +28,7 @@ class DownloadFactory:
         sanitised_url = DownloadFactory.sanitise_url(url)
         if re.match(r"(i\.|m\.)?imgur", sanitised_url):
             return Imgur
-        elif re.match(r"(i\.|thumbs\d\.)?(redgifs|gifdeliverynetwork)", sanitised_url):
+        elif re.match(r"(i\.|thumbs\d\.|v\d\.)?(redgifs|gifdeliverynetwork)", sanitised_url):
             return Redgifs
         elif re.match(r".*/.*\.[a-zA-Z34]{3,4}(\?[\w;&=]*)?$", sanitised_url) and not DownloadFactory.is_web_resource(
             sanitised_url