I am running Mattermost with Docker. After upgrade I have it:
web_1 | 2019/08/31 15:22:50 [warn] 1#1: the "ssl" directive is deprecated, use the "listen ... ssl" directive instead in /etc/nginx/conf.d/mattermost.conf:15
web_1 | nginx: [warn] the "ssl" directive is deprecated, use the "listen ... ssl" directive instead in /etc/nginx/conf.d/mattermost.conf:15
Additionally, may I know what version were you originally running on prior to the upgrade please? Can you also share the documentation you referred to for upgrading your Mattermost? Thanks.