fix docker image build

Author: stephanediondev

Dockerfile

@@ -17,7 +17,7 @@ RUN apk --update add php7 php7-fpm php7-opcache php7-json php7-openssl php7-curl
     php7-zlib php7-xml php7-simplexml php7-phar php7-intl php7-dom php7-xmlreader php7-ctype php7-session \
     php7-tokenizer php7-pdo php7-pdo_mysql php7-pdo_pgsql php7-iconv php7-zip \
     php7-gmp php7-mbstring nginx supervisor nodejs nodejs npm curl && \
-    rm /etc/nginx/conf.d/default.conf
+    rm -f /etc/nginx/conf.d/default.conf
 
 # Configure nginx
 COPY docker/nginx.conf /etc/nginx/nginx.conf