hls, webrtc: fix appending slash to paths that contain slashes (#2773)

internal/protocols/httpserv/location_with_trailing_slash.go

@@ -4,9 +4,19 @@ import "net/url"
 
 // LocationWithTrailingSlash returns the URL in a relative format, with a trailing slash.
 func LocationWithTrailingSlash(u *url.URL) string {
-	l := "./" + u.Path[1:] + "/"
+	l := "./"
+
+	for i := 1; i < len(u.Path); i++ {
+		if u.Path[i] == '/' {
+			l += "../"
+		}
+	}
+
+	l += u.Path[1:] + "/"
+
 	if u.RawQuery != "" {
 		l += "?" + u.RawQuery
 	}
+
 	return l
 }