koreus.lua: tighten URL probe function

Ref. #17488

share/lua/playlist/koreus.lua

@@ -19,14 +19,9 @@
 
 -- Probe function.
 function probe()
-    if vlc.access ~= "http" and vlc.access ~= "https" then
-        return false
-    end
-    koreus_site = string.match( vlc.path, "koreus" )
-    if not koreus_site then
-        return false
-    end
-    return (  string.match( vlc.path, "video" )  ) -- http://www.koreus.com/video/pouet.html
+    local path = vlc.path:gsub("^www%.", "")
+    return ( vlc.access == "http" or vlc.access == "https" )
+        and string.match( path, "^koreus%.com/video/.+" )
 end
 
 -- Parse function.