squid: downgrade to 3.5.15.

Revert to the latest stable.

srcpkgs/squid/template

@@ -1,6 +1,7 @@
 # Template file for 'squid'
 pkgname=squid
-version=4.0.6
+reverts="4.0.6 4.0.5 4.0.3 4.0.2 4.0.1"
+version=3.5.15
 revision=1
 build_style=gnu-configure
 configure_args="
@@ -58,7 +59,7 @@ maintainer="Toyam Cox <Vaelatern@gmail.com>"
 license="GPL-2"
 homepage="http://www.squid-cache.org/"
 distfiles="ftp://ftp.fu-berlin.de/unix/www/${pkgname}/${pkgname}/${pkgname}-${version}.tar.xz"
-checksum=896fd5a33365aac51e122b273de2ddcd50003b909608ca3ac635bd7f12ca139b
+checksum=9cfce3231c7b3b33816fc54414d8720a51ac5e723663e0685a8bb995b9f450d2
 nocross=yes
 
 post_install() {