Update www/squid package to 3.0.17 (3.0.STABLE17).

Changes to squid-3.0.STABLE17 (27 Jul 2009):

- Bug 2680 regression: Crash after rotate with no helpers running
- Bug 2710: squid_kerb_auth non-terminated string
- Bug 2679: strsep and strtoll detection failure
- Bug 2674: Remove limit on HTTP headers read.
- Bug 2659: String length overflows on append, leading to segfaults
- Bug 2620: Invalid HTTP response codes causes segfault
- Bug 2080: wbinfo_group.pl - false positive under certain conditions
- Bug 1087: ESI processor not quoting attributes correctly.
- Fix: issue with AUFS/UFS/DiskD writing objects to disk cache
- Several small build issues with previous release.

(taca)