[sagher]

@rudra  Ok. as you said. i replace those two lines into sources.list
and then again try command apt-get update

long stuck at 98% ... at the end.

root@xxxxxxxxxxxx:~# apt-get update
Get:1 http://deb.debian.org/debian buster InRelease [158 kB]
Get:2 http://security.debian.org buster/updates InRelease [38.3 kB]
Ign:3 https://packages.sury.org/php stretch InRelease
Get:4 http://deb.debian.org/debian buster/main amd64 Packages [7966 kB]
Ign:5 https://packages.sury.org/php stretch Release
Ign:6 https://packages.sury.org/php stretch/main amd64 Packages
Get:7 http://deb.debian.org/debian buster/main Translation-en [5990 kB]
Ign:8 https://packages.sury.org/php stretch/main all Packages
Get:9 http://deb.debian.org/debian buster/contrib amd64 Packages [52.8 kB]
Get:10 http://deb.debian.org/debian buster/contrib Translation-en [46.1 kB]
Get:11 http://deb.debian.org/debian buster/non-free amd64 Packages [88.3 kB]
Get:12 http://deb.debian.org/debian buster/non-free Translation-en [88.8 kB]
Ign:13 https://packages.sury.org/php stretch/main Translation-en
Ign:6 https://packages.sury.org/php stretch/main amd64 Packages
Ign:8 https://packages.sury.org/php stretch/main all Packages
Ign:13 https://packages.sury.org/php stretch/main Translation-en
Ign:6 https://packages.sury.org/php stretch/main amd64 Packages
Ign:8 https://packages.sury.org/php stretch/main all Packages
Ign:13 https://packages.sury.org/php stretch/main Translation-en
Ign:6 https://packages.sury.org/php stretch/main amd64 Packages
Ign:8 https://packages.sury.org/php stretch/main all Packages
Ign:13 https://packages.sury.org/php stretch/main Translation-en
Ign:6 https://packages.sury.org/php stretch/main amd64 Packages
Ign:8 https://packages.sury.org/php stretch/main all Packages
Ign:13 https://packages.sury.org/php stretch/main Translation-en
Err:6 https://packages.sury.org/php stretch/main amd64 Packages
 The HTTP server sent an invalid reply header
Ign:8 https://packages.sury.org/php stretch/main all Packages
Ign:13 https://packages.sury.org/php stretch/main Translation-en
Fetched 14.4 MB in 6min 5s (39.4 kB/s)
Reading package lists... Done
W: The repository 'https://packages.sury.org/php stretch Release' does not have a Release file.
N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use.
N: See apt-secure(8) manpage for repository creation and user configuration details.
E: Failed to fetch https://packages.sury.org/php/dists/stre...4/Packages  The HTTP server sent an invalid reply header
E: Some index files failed to download. They have been ignored, or old ones used instead.

now time for apt dist-upgrade

root@xxxxxxxxxxxxxxxx:~# apt dist-upgrade
Reading package lists... Done
Building dependency tree
Reading state information... Done
Calculating upgrade... Error!
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
dpkg : Breaks: libapt-pkg5.0 (< 1.7~b) but 1.4.8 is to be installed
E: Error, pkgProblemResolver::Resolve generated breaks, this may be caused by held packages.