Upgrade default image version from 2.7.1 to 2.8.1

Includes changes from releases 2.8.0 and 2.8.1, which mostly contain bugfixes:

- https://github.com/distribution/distribution/releases/tag/v2.8.0
- https://github.com/distribution/distribution/releases/tag/v2.8.1

Chart.yaml

@@ -2,7 +2,7 @@ apiVersion: v1
 description: A Helm chart for Docker Registry
 name: docker-registry
 version: 2.2.1
-appVersion: 2.7.1
+appVersion: 2.8.1
 home: https://hub.docker.com/_/registry/
 icon: https://helm.twun.io/docker-registry.png
 maintainers:

values.yaml

@@ -19,7 +19,7 @@ serviceAccount:
 
 image:
   repository: registry
-  tag: 2.7.1
+  tag: 2.8.1
   pullPolicy: IfNotPresent
 # imagePullSecrets:
     # - name: docker