upgrade: provide DOMAIN to the server upgrade dictionary

Rules in ipa-rewrite.conf use $DOMAIN variable but it is not available
in the dictionary. Regression was introduced with
e731b2725a.

Fixes: https://pagure.io/freeipa/issue/8615
Related: https://pagure.io/freeipa/issue/8595

Signed-off-by: Alexander Bokovoy <abokovoy@redhat.com>
Reviewed-By: Florence Blanc-Renaud <frenaud@redhat.com>

ipaserver/install/server/upgrade.py

@@ -1578,6 +1578,7 @@ def upgrade_configuration():
         IPA_CCACHES=paths.IPA_CCACHES,
         IPA_CUSTODIA_SOCKET=paths.IPA_CUSTODIA_SOCKET,
         KDCPROXY_CONFIG=paths.KDCPROXY_CONFIG,
+        DOMAIN=api.env.domain,
     )
 
     subject_base = find_subject_base()