squid: Update to 4.13

squid: Update to 4.13

For details see:
http://www.squid-cache.org/Versions/v4/changesets/

and

http://lists.squid-cache.org/pipermail/squid-users/2020-August/022566.html

Fixes (excerpt):

"* SQUID-2020:8 HTTP(S) Request Splitting
   (CVE-2020-15811)

This problem is serious because it allows any client, including
browser scripts, to bypass local security and poison the browser
cache and any downstream caches with content from an arbitrary
source.

* SQUID-2020:9 Denial of Service processing Cache Digest Response
   (CVE pending allocation)

This problem allows a trusted peer to deliver to perform Denial
of Service by consuming all available CPU cycles on the machine
running Squid when handling a crafted Cache Digest response
message.

* SQUID-2020:10 HTTP(S) Request Smuggling
   (CVE-2020-15810)

This problem is serious because it allows any client, including
browser scripts, to bypass local security and poison the proxy
cache and any downstream caches with content from an arbitrary
source.

* Bug 5051: Some collapsed revalidation responses never expire

* SSL-Bump: Support parsing GREASEd (and future) TLS handshakes

* Honor on_unsupported_protocol for intercepted https_port"

Signed-off-by: Matthias Fischer <matthias.fischer@ipfire.org>
Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>