Update st2web/Dockerfile

Co-authored-by: Jacob Floyd <cognifloyd@gmail.com>

Author: jk464

st2web/Dockerfile

@@ -83,5 +83,5 @@ EXPOSE 443
 EXPOSE 8080
 EXPOSE 8443
 STOPSIGNAL SIGTERM
-RUN touch /var/run/nginx.pid && chown 999:999 /etc/nginx/conf.d/ /var/cache/nginx/ /var/run/nginx.pid
+RUN touch /var/run/nginx.pid && chown nginx:nginx /etc/nginx/conf.d/ /var/cache/nginx/ /var/run/nginx.pid
 CMD ["/bin/bash", "-c", "if [ ${ST2WEB_HTTPS} = 1 ]; then ST2WEB_TEMPLATE='/etc/nginx/conf.d/st2-https.template'; else ST2WEB_TEMPLATE='/etc/nginx/conf.d/st2-http.template'; fi && envsubst '${ST2_AUTH_URL} ${ST2_API_URL} ${ST2_STREAM_URL} ${ST2_PORT_HTTP} ${ST2_PORT_HTTPS}' < ${ST2WEB_TEMPLATE} > /etc/nginx/conf.d/st2.conf && exec nginx -g 'daemon off;'"]