Update Dockerfile for tauschen #52

Job	Run time
Build App Containers (etherpad) / Build etherpad	14m 30s
Build App Containers (limesurvey) / Build limesurvey	56s
Build App Containers (indico) / Build indico	2m 18s
Build App Containers (minecraft) / Build minecraft	20s
Build App Containers (nextcloud) / Build nextcloud	1m 39s
Build App Containers (sogo) / Build sogo	3m 7s
	22m 50s

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