Update chart dependencies with new mongodb and mariadb (#438)

charts/ghost/Chart.lock

charts/ghost/Chart.yaml

charts/ghost/README.md

charts/ghost/charts/mariadb-0.2.11.tgz

charts/ghost/charts/mariadb-0.2.12.tgz

charts/gitea/Chart.lock

charts/gitea/Chart.yaml

charts/gitea/README.md

charts/gitea/charts/mariadb-0.2.11.tgz

charts/gitea/charts/mariadb-0.2.12.tgz

charts/graylog/Chart.lock

charts/graylog/Chart.yaml

charts/graylog/README.md

charts/graylog/charts/mongodb-0.2.12.tgz

charts/graylog/charts/mongodb-0.2.13.tgz

charts/nextcloud/Chart.lock

charts/nextcloud/Chart.yaml

charts/nextcloud/README.md

charts/nextcloud/charts/mariadb-0.2.11.tgz

charts/nextcloud/charts/mariadb-0.2.12.tgz