Use specific docker image tags to allow drone to cache them and not run into docker pull rate limits
Use specific docker image tags to allow drone to cache them and not run into docker pull rate limits

Signed-off-by: Morris Jobke <7f550a9f4c44173a37664d938f1355f0f92a47a7@morrisjobke.de>

nextcloud/server,nextcloud/server,nextcloud/server,nextcloud/server