When using --http-addr 0.0.0.0:8443 (to bind to IPv4 only), the URL
construction was broken, producing URLs like https://192.168.31.110.0.0.0:8443
Now correctly extracts the port number from both ":8443" and "0.0.0.0:8443"
formats using ${HTTP_ADDR##*:} instead of ${HTTP_ADDR#:}
Related to #805