Revert "Fix quic-go leaking connections"

This reverts commit fcad2b6.

Author: nekohasekai

common/baderror/baderror.go

@@ -53,9 +53,6 @@ func WrapQUIC(err error) error {
 	if err == nil {
 		return nil
 	}
-	if errors.Is(err, io.EOF) {
-		return io.ErrUnexpectedEOF
-	}
 	if Contains(err,
 		"canceled by remote with error code 0",
 		"canceled by local with error code 0",