It seems the archive.openwrt.org site is down:
curl -v https://archive.openwrt.org
* Rebuilt URL to: https://archive.openwrt.org/
* Trying 81.0.124.218...
* TCP_NODELAY set
* Connection failed
* connect to 81.0.124.218 port 443 failed: Connection refused
* Failed to connect to archive.openwrt.org port 443: Connection refused
* Closing connection 0
curl: (7) Failed to connect to archive.openwrt.org port 443: Connection refused