Update vendored library github.com/ncw/swift

Gopkg.lock

@@ -113,7 +113,7 @@
   branch = "master"
   name = "github.com/ncw/swift"
   packages = ["."]
-  revision = "ae9f0ea1605b9aa6434ed5c731ca35d83ba67c55"
+  revision = "b2a7479cf26fa841ff90dd932d0221cb5c50782d"
 
 [[projects]]
   name = "github.com/pkg/errors"

vendor/github.com/ncw/swift/swift.go

@@ -1843,7 +1843,8 @@ type BulkDeleteResult struct {
 func (c *Connection) doBulkDelete(objects []string) (result BulkDeleteResult, err error) {
 	var buffer bytes.Buffer
 	for _, s := range objects {
-		buffer.WriteString(url.QueryEscape(s) + "\n")
+		u := url.URL{Path: s}
+		buffer.WriteString(u.String() + "\n")
 	}
 	resp, headers, err := c.storage(RequestOpts{
 		Operation:  "DELETE",
@@ -1851,6 +1852,7 @@ func (c *Connection) doBulkDelete(objects []string) (result BulkDeleteResult, er
 		Headers: Headers{
 			"Accept":         "application/json",
 			"Content-Type":   "text/plain",
+			"Content-Length": strconv.Itoa(buffer.Len()),
 		},
 		ErrorMap: ContainerErrorMap,
 		Body:     &buffer,