Fix envsubst undefined behaviour on some platforms in Dockerfile

Dockerfile

@@ -78,7 +78,7 @@ COPY nginx/components/ ${TFW_NGINX_COMPONENTS}
 RUN chown -R ${AVATAO_USER} /var/log/nginx /var/lib/nginx                               &&\
     sed -i 's#pid /run/nginx.pid;#pid /tmp/nginx.pid;#g' /etc/nginx/nginx.conf          &&\
     for f in "${TFW_NGINX_CONF}" ${TFW_NGINX_COMPONENTS}/*.conf; do                    \
-        envsubst "$(printenv | cut -d= -f1 | grep TFW_ | sed -e 's/^/$/g')" < $f > $f ;\
+        envsubst "$(printenv | cut -d= -f1 | grep TFW_ | sed -e 's/^/$/g')" < $f > $f~ && mv $f~ $f ;\
     done
 
 COPY supervisor/supervisord.conf ${TFW_SUPERVISORD_CONF}