Updating gpg keys

src/freedombone-base-email

         echo "$GPG_REFRESH_TIME            */$REFRESH_GPG_KEYS_HOURS *   *   *   root cronic $REFRESH_GPG_KEYS_SCRIPT" >> /etc/crontab
         systemctl restart cron
     else
-        sed -i "s|root $REFRESH_GPG_KEYS_SCRIPT.*|root cronic $REFRESH_GPG_KEYS_SCRIPT|g" /etc/crontab
+        if ! grep "root cronic $REFRESH_GPG_KEYS_SCRIPT" /etc/crontab; then
+            sed -i "s|root $REFRESH_GPG_KEYS_SCRIPT.*|root cronic $REFRESH_GPG_KEYS_SCRIPT|g" /etc/crontab
+        fi
     fi
 }