Add admin handler to list of handlers used for background tasks (#17847)

Fixes #17823

While we're at it, makes a change where the redactions are sent as the
admin if the user is not a member of the server (otherwise these fail
with a "User must be our own" message).

1 files changed, 1 insertions, 0 deletions

diff --git a/synapse/server.py b/synapse/server.py

index 318c6abf3d..c7b4918813 100644
--- a/synapse/server.py
+++ b/synapse/server.py
@@ -249,6 +249,7 @@ class HomeServer(metaclass=abc.ABCMeta):
     """
 
     REQUIRED_ON_BACKGROUND_TASK_STARTUP = [
+        "admin",
         "account_validity",
         "auth",
         "deactivate_account",