app: use default cmd (#49)

Author: rm-yakovenko

docker/app/Dockerfile

@@ -30,5 +30,4 @@ ARG XDEBUG
 
 RUN if [ $XDEBUG ]; then pecl install xdebug && docker-php-ext-enable xdebug; fi
 
-USER app
-CMD ["php-fpm", "-F", "-R"]
+USER app