move hack to client

vendor/github.com/go-openapi/swag/pre_go18.go

@@ -1,23 +0,0 @@
-// Copyright 2015 go-swagger maintainers
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//    http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-// +build !go1.8
-
-package swag
-
-import "net/url"
-
-func pathUnescape(path string) (string, error) {
-	return url.QueryUnescape(path)
-}