Remove obsolete patch.

Since a tails-iuk package with those fixes has been uploaded.

config/chroot_local-patches/iuk-handle-website-CA-change.patch

---- a/usr/share/perl5/Tails/IUK.pm
-+++ b/usr/share/perl5/Tails/IUK.pm
-@@ -255,6 +255,7 @@ method _build_squashfs_diff  {
- 
-     run_as_root(
-         "rsync", "--archive", "--quiet", "--delete-after", "--acls",
-+        "--checksum",
-         sprintf("%s/", dir($new_squashfs_mount)),
-         sprintf("%s/", dir($union)),
-     );
---- a/usr/share/perl5/Tails/IUK/UpgradeDescriptionFile/Download.pm
-+++ b/usr/share/perl5/Tails/IUK/UpgradeDescriptionFile/Download.pm
-@@ -105,7 +105,7 @@ method _build_curl_opts {
-     }
-     else {
-         my $cafile = $ENV{HTTPS_CA_FILE};
--        $cafile  //= '/etc/ssl/certs/UTN_USERFirst_Hardware_Root_CA.pem';
-+        $cafile  //= '/usr/local/etc/ssl/certs/tails.boum.org-CA.pem';
-         push @opts, CURLOPT_SSL_VERIFYHOST,  2;
-         push @opts, CURLOPT_SSL_VERIFYPEER,  1;
-         push @opts, CURLOPT_CAINFO,          $cafile;