www/c-icap: Upgrade to 0.5.7

Major changes:

• Fix brotli performance
• Fix various memory leaks
• c-icap-stretch utility: Fix HTTP response status line
• c-icap-stretch: send always an HTTP/1.1 request
• Update accepted flags for tls-options option of TlsPort cfg parameter
• ICAP client: support SSL connections to hostnames that contain IP addresses
• Bug fix: False accepting connection errors