package/liblinear: fix _SITE url

The package _SITE url only contains the latest version at a given point
in time. When a new version is published, it is replacing the old one.

This issue was not detected because the archive was downloaded from the
sources.buildroot.org backup mirror, when the primary source became
unavailable.

Since commit 559bb33ae "support/testing: do not use s.b.o" [1], the
runtime test infrastructure is disabling this backup mirror. This
makes the nmap runtime test failing [2], which is using liblinear as
a dependency.

The liblinear package author confirmed in a private email that all the
releases, including the latest version, are all kept in the "oldfiles"
directory.

This commit fixes this download issue by updating the _SITE url to that
location. While at it, this commit also change the url to use https
(since the http equivalent redirects to https).

Fixes:
- [2]

[1] 559bb33ae7
[2] https://gitlab.com/buildroot.org/buildroot/-/jobs/7948008007

Signed-off-by: Julien Olivain <ju.o@free.fr>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
(cherry picked from commit 8b18c67f2651ac64e865a1dbd46de60ce8390959)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/liblinear/liblinear.mk

@@ -5,7 +5,7 @@
 ################################################################################
 
 LIBLINEAR_VERSION = 2.45
-LIBLINEAR_SITE = http://www.csie.ntu.edu.tw/~cjlin/liblinear
+LIBLINEAR_SITE = https://www.csie.ntu.edu.tw/~cjlin/liblinear/oldfiles
 LIBLINEAR_LICENSE = BSD-3-Clause
 LIBLINEAR_LICENSE_FILES = COPYRIGHT
 LIBLINEAR_INSTALL_STAGING = YES