fix for /bin/sh alpine

Author: Raphaël Droz

docker-entrypoint.sh

@@ -126,7 +126,7 @@ if [[ "$1" == apache2* ]] || [ "$1" == php-fpm ]; then
 		: "${WORDPRESS_DB_PASSWORD:=}"
 		: "${WORDPRESS_DB_NAME:=wordpress}"
 
-		if [ -e wp-config.php && -n $NO_AUTO_CONFIG ]; then
+		if [ -e wp-config.php && -n "$NO_AUTO_CONFIG" ]; then
 			exec "$@"
 		fi
 		if [ -e wp-config.php && ! -w wp-config.php ]; then