snapshot: removed content stats from snapshot.Stats, which are confusing and incorrect if snapshots are done in parallel

snapshot/snapshotfs/upload.go

@@ -780,7 +780,6 @@ func (u *Uploader) Upload(
 	s.IncompleteReason = u.cancelReason()
 	s.EndTime = time.Now()
 	s.Stats = u.stats
-	s.Stats.Content = u.repo.Content.Stats()
 
 	return s, nil
 }

snapshot/stats.go

@@ -2,13 +2,10 @@
 
 import (
 	"github.com/kopia/kopia/fs"
-	"github.com/kopia/kopia/repo/content"
 )
 
 // Stats keeps track of snapshot generation statistics.
 type Stats struct {
-	Content content.Stats `json:"content,omitempty"`
-
 	TotalDirectoryCount int   `json:"dirCount"`
 	TotalFileCount      int   `json:"fileCount"`
 	TotalFileSize       int64 `json:"totalSize"`