slapos_web_deploy: add support for old Debian 10

In old Debian 10, after the release of Debian 11, apt update is failing
like this if we don't add the option "--allow-releaseinfo-change":

root@debian:~# apt update
Get:1 http://security.debian.org/debian-security buster/updates InRelease [65.4 kB]
Get:2 http://http.us.debian.org/debian buster InRelease [122 kB]
E: Repository 'http://security.debian.org/debian-security buster/updates InRelease' changed its 'Suite' value from 'stable' to 'oldstable'
N: This must be accepted explicitly before updates for this repository can be applied. See apt-secure(8) manpage for details.

master/bt5/slapos_web_deploy/PathTemplateItem/web_page_module/deploy_function_common.txt

@@ -1028,7 +1028,7 @@ function update_package_repo {
         if [[ "$REPOS_UPDATED" != "True" || "$RETRY_UPDATE" = "True" ]]; then
             # if there are transient errors pulling the updates, that's fine.
             # It may be secondary repositories that we don't really care about.
-            apt_get update  || /bin/true
+            apt_get update --allow-releaseinfo-change || /bin/true
             REPOS_UPDATED=True
         fi
         $xtrace