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/livedoor.py

@@ -84,7 +84,7 @@ class LivedoorExtractor(Extractor):
 class LivedoorBlogExtractor(LivedoorExtractor):
     """Extractor for a user's blog on blog.livedoor.jp"""
     subcategory = "blog"
-    pattern = r"(?:https?://)?blog\.livedoor\.jp/(\w+)/?(?:$|[?&#])"
+    pattern = r"(?:https?://)?blog\.livedoor\.jp/(\w+)/?(?:$|[?#])"
     test = (
         ("http://blog.livedoor.jp/zatsu_ke/", {
             "range": "1-50",