Enable Matrix message thread support.

This change enables experimental message threading support and upgrades
Synapse and Element to their latest stable versions.

Change-Id: I68334982168ffdac98a1602a157be727b04e58d6
Reviewed-on: https://gerrit.hackerspace.pl/c/hscloud/+/1286
Reviewed-by: informatic <informatic@hackerspace.pl>
Reviewed-by: q3k <q3k@hackerspace.pl>
diff --git a/app/matrix/lib/synapse/homeserver-ng.yaml b/app/matrix/lib/synapse/homeserver-ng.yaml
index 7d0a98a..3e11a1e 100644
--- a/app/matrix/lib/synapse/homeserver-ng.yaml
+++ b/app/matrix/lib/synapse/homeserver-ng.yaml
@@ -130,3 +130,8 @@
 # Allow federated public rooms browsing

 allow_public_rooms_without_auth: true

 allow_public_rooms_over_federation: true

+

+## Experimental Features ##

+experimental_features:

+  # Message threading support

+  msc3440_enabled: true