Remove STOPSIGNAL from dockerfile

Author: Kate Osborn

build/Dockerfile.nginx

@@ -16,5 +16,3 @@ COPY ${NGINX_CONF_DIR}/nginx.conf /etc/nginx/nginx.conf
 RUN chown -R 101:1001 /etc/nginx /var/cache/nginx /var/lib/nginx
 
 USER 101:1001
-
-STOPSIGNAL SIGTERM