create initial user in postinst script

debian/openwebrx.postinst

@@ -12,6 +12,9 @@ case "$1" in
     # create OpenWebRX data directory and set the correct permissions
     if [ ! -d "${OWRX_DATADIR}" ] && [ ! -L "${OWRX_DATADIR}" ]; then mkdir "${OWRX_DATADIR}"; fi
     chown -R "${OWRX_USER}". ${OWRX_DATADIR}
+
+    # create initial openwebrx user
+    openwebrx-admin adduser --noninteractive --silent --user admin
   ;;
   *)
     echo "postinst called with unknown argument '$1'" 1>&2