fix ENV format

Dockerfile

@@ -20,7 +20,7 @@ ENV LANGUAGE=${BUILD_LANGUAGE}
 ENV LC_ALL=${BUILD_LC_ALL}
 ENV COUNTRY=${BUILD_COUNTRY}
 ENV DEBIAN_FRONTEND=noninteractive
-ENV BASE_PACKAGES=$(BUILD_BASE_PACKAGES)
+ENV BASE_PACKAGES=${BUILD_BASE_PACKAGES}
 
 RUN sed -i 's/^Types: deb$/Types: deb deb-src/' /etc/apt/sources.list.d/debian.sources && \
     apt-get update && apt-get install -y --no-install-recommends \