use own pretix docker image for more plugins

pretix/init.sls

@@ -3,7 +3,7 @@
 {% set docker = salt['pillar.get']('docker', {}) %}
 {% set pretix = salt['pillar.get']('pretix', {}) %}
 {% set volume = docker.volume_root ~ '/pretix' %}
-{% set image = 'pretix/standalone:stable' %}
+{% set image = 'docker.chaos.expert/ffffm/container/pretix:latest' %}
 {% set postgres_image = 'postgres:17.2' %}
 
 include: