Allow runtime configuration of nginx listening port

Author: sarayourfriend

frontend/Dockerfile.nginx

@@ -27,3 +27,4 @@ ENV OPENVERSE_NGINX_ENVIRONMENT="local"
 # Add the release version to the docker container
 ARG SEMANTIC_VERSION
 ENV OPENVERSE_NGINX_GIT_REVISION=$SEMANTIC_VERSION
+ENV OPENVERSE_NGINX_LISTEN_PORT="8080"

frontend/nginx.conf.template

@@ -45,7 +45,7 @@ upstream ov_service {
 server {
     access_log  /var/log/nginx/access.log  json_combined;
 
-    listen          8080;
+    listen          $OPENVERSE_NGINX_LISTEN_PORT;
     server_name     _;
     charset        utf-8;
     client_max_body_size 75M;