rebase: bump github.com/ceph/go-ceph from 0.19.0 to 0.20.0

Bumps [github.com/ceph/go-ceph](https://github.com/ceph/go-ceph) from 0.19.0 to 0.20.0.
- [Release notes](https://github.com/ceph/go-ceph/releases)
- [Changelog](https://github.com/ceph/go-ceph/blob/master/docs/release-process.md)
- [Commits](https://github.com/ceph/go-ceph/compare/v0.19.0...v0.20.0)

---
updated-dependencies:
- dependency-name: github.com/ceph/go-ceph
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

vendor/github.com/ceph/go-ceph/common/admin/nfs/export.go

@@ -4,6 +4,8 @@
 package nfs
 
 import (
+	"errors"
+
 	"github.com/ceph/go-ceph/internal/commands"
 )
 
@@ -26,6 +28,10 @@ const (
 	Unspecifiedquash SquashMode = ""
 )
 
+var (
+	errNoExportInfo = errors.New("No export info found")
+)
+
 // SecType indicates the kind of security/authentication to be used by an export.
 type SecType string
 
@@ -115,6 +121,11 @@ func parseExportsList(res commands.Response) ([]ExportInfo, error) {
 
 func parseExportInfo(res commands.Response) (ExportInfo, error) {
 	i := ExportInfo{}
+	// different versions of ceph may return nothing or empty json.
+	// detect these cases and return a specific error
+	if res.NoStatus().EmptyBody().Ok() {
+		return i, errNoExportInfo
+	}
 	if err := res.NoStatus().Unmarshal(&i).End(); err != nil {
 		return i, err
 	}