feat(postprocessing): dont retry finished uploads

Signed-off-by: jkoberg <jkoberg@owncloud.com>

services/postprocessing/pkg/postprocessing/postprocessing.go

@@ -22,6 +22,7 @@ type Postprocessing struct {
 	Status      Status
 	Failures    int
 	InitiatorID string
+	Finished    bool
 
 	config config.Postprocessing
 }