Update www/squid package to 2.6.21 (2.6.STABLE21) which contains
two security fixes:

- Bug #1993: Memory leak in http_reply_access deny processing
- Bug #2122: In some situations collapsed_forwarding could leak
  private information

Changes to squid-2.6.STABLE21 (27 June 2008)

- Bug #2350: Bugs in Linux kernel capabilities code
- Bug #2241: weights not applied properly in round-robin peer
  selection
- Off by one error in DNS label decompression could cause valid DNS
  messages to be rejected
- logformat docs contain extra whitespace
- Reject ridiculously large ASN.1 lengths
- Fix SNMP reporting of counters with a value > 0xFF80000
- Correct spelling of WCCPv2 dst_port_hash to match the source
- Plug some "squid -k reconfigure" memory leaks. Mostly SSL related.
- Bug #1993: Memory leak in http_reply_access deny processing
- Bug #2122: In some situations collapsed_forwarding could leak
  private information
- Bug #2376: Round-Robin becomes unbalanced when a peer dies and comes
  back
- Bug #2387: The calculation of the number of hash buckets need to
  account for the memory size, not only disk size
- Bug #2393: DNS requests retried indefinitely at full speed on failed
  TCP connection
- Bug #2393: DNS retransmit queue could get hold up
- Correct socket syscalls statistics in commResetFD()

(taca)