Revert last commit

Dockerfile

@@ -1,7 +1,5 @@
 FROM node:latest
 
-LABEL org.label-schema.usage="https://code.r3pek.org/r3pek/docker-haraka/raw/branch/master/README.md"
-
 ENV HOSTNAME=${HOSTNAME:-haraka.localdomain}
 ENV EMAIL=${EMAIL:-test@email.tld}
 ENV USE_LETSENCRYPT=${USE_LETSENCRYPT:-false}