Correctly define default values in Dockerfile

Author: wiktorn

Dockerfile

@@ -92,9 +92,9 @@ COPY docker-entrypoint.sh docker-healthcheck.sh /app/
 RUN chmod a+rx /app/docker-entrypoint.sh /app/bin/update_overpass.sh /app/bin/rules_loop.sh /app/bin/dispatcher_start.sh \
     /app/bin/oauth_cookie_client.py /app/bin/start_fcgiwarp.sh
 
-ENV OVERPASS_RULES_LOAD=${OVERPASS_RULES_LOAD:-1}
-ENV OVERPASS_USE_AREAS=${OVERPASS_USE_AREAS:-true}
-ENV OVERPASS_ALLOW_DUPLICATE_QUERIES=${OVERPASS_ALLOW_DUPLICATE_QUERIES:-no}
+ENV OVERPASS_RULES_LOAD=1
+ENV OVERPASS_USE_AREAS=true
+ENV OVERPASS_ALLOW_DUPLICATE_QUERIES=no
 
 EXPOSE 80