Update chart dependencies (#867)

charts/commento/Chart.lock

charts/commento/Chart.yaml

charts/commento/README.md

charts/commento/RELEASENOTES.md

charts/commento/charts/postgres-0.2.16.tgz

charts/commento/charts/postgres-0.2.17.tgz

charts/ghost/Chart.lock

charts/ghost/Chart.yaml

charts/ghost/README.md

charts/ghost/RELEASENOTES.md

charts/ghost/charts/mariadb-0.2.17.tgz

charts/ghost/charts/mariadb-0.2.18.tgz

charts/gitea/Chart.lock

charts/gitea/Chart.yaml

charts/gitea/README.md

charts/gitea/RELEASENOTES.md

charts/gitea/charts/mariadb-0.2.17.tgz

charts/gitea/charts/mariadb-0.2.18.tgz

charts/gitea/charts/postgres-0.2.16.tgz

charts/gitea/charts/postgres-0.2.17.tgz