xep-0313: use default archive preference from server

The user message archiving default retrieved from the server should be
maintained and not overridden.
7 jobs for mam_pref_fix in 8 minutes (queued for 1 second)
Status Job ID Name Coverage
  Build
passed #363504
librem5
build-pureos-gcc-byzantium

00:01:41

 
  Test
passed #363506
librem5
check-po

00:00:18

passed #363505
librem5
test:debian-gcc

00:01:32

21.8%
 
  Package
passed #363507
librem5
package-pureos-byzantium

00:01:35

passed #363508
librem5:arm64
package-pureos-byzantium:arm64

00:04:45

 
  Test Package
passed #363509
librem5
autopkgtest-pureos-byzantium-package

00:01:13

passed #363510
librem5
lintian-pureos-byzantium-package

00:00:42