ytdl_hook.lua: lower case URLs for exclude matching

DOCS/man/options.rst

@@ -907,6 +907,8 @@ Program Behavior
         should use ``%`` before any of the characters ``^$()%|,.[]*+-?`` to
         match that character.
 
+        URLs are converted to lower case before matching.
+
         .. admonition:: Examples
 
             - ``--script-opts=ytdl_hook-exclude='^youtube%.com'``

player/lua/ytdl_hook.lua

@@ -291,7 +291,7 @@ local function is_blacklisted(url)
         end
     end
     if #ytdl.blacklisted > 0 then
-        url = url:match('https?://(.+)')
+        url = url:match('https?://(.+)'):lower()
         for _, exclude in ipairs(ytdl.blacklisted) do
             if url:match(exclude) then
                 msg.verbose('URL matches excluded substring. Skipping.')