[Dockerfiles] Use COPY instead of ADD

data/Dockerfiles/clamav/Dockerfile

@@ -40,5 +40,5 @@ VOLUME ["/var/lib/clamav"]
 EXPOSE 3310
 
 # av daemon bootstrapping
-ADD bootstrap.sh /
+COPY bootstrap.sh /
 CMD ["/bootstrap.sh"]

data/Dockerfiles/rspamd/Dockerfile

@@ -16,8 +16,8 @@ RUN apt-key adv --fetch-keys http://rspamd.com/apt-stable/gpg.key \
 
 RUN echo '.include $LOCAL_CONFDIR/local.d/rspamd.conf.local' > /etc/rspamd/rspamd.conf.local
 
-ADD settings.conf /etc/rspamd/modules.d/settings.conf
-ADD antivirus.conf /etc/rspamd/modules.d/antivirus.conf
+COPY settings.conf /etc/rspamd/modules.d/settings.conf
+COPY antivirus.conf /etc/rspamd/modules.d/antivirus.conf
 
 RUN pip install -U oletools