remove '&' from URL patterns

'/?&#' -> '/?#' and '?&#' -> '?#'

According to https://www.ietf.org/rfc/rfc3986.txt, URLs are
"organized hierarchically" by using "the slash ("/"), question
mark ("?"), and number sign ("#") characters to delimit components"

gallery_dl/extractor/imagefap.py

@@ -151,7 +151,7 @@ class ImagefapUserExtractor(ImagefapExtractor):
     subcategory = "user"
     categorytransfer = True
     pattern = (BASE_PATTERN +
-               r"/(?:profile(?:\.php\?user=|/)([^/?&#]+)"
+               r"/(?:profile(?:\.php\?user=|/)([^/?#]+)"
                r"|usergallery\.php\?userid=(\d+))")
     test = (
         ("https://www.imagefap.com/profile/LucyRae/galleries", {