Use delete room API v2 (delete room in background) (#211)

Co-authored-by: Michael Albert <37796947+awesome-michael@users.noreply.github.com>

README.md

@@ -13,7 +13,7 @@ This project is built using [react-admin](https://marmelab.com/react-admin/).
 
 ### Supported Synapse
 
-It needs at least [Synapse](https://github.com/matrix-org/synapse) v1.46.0 for all functions to work as expected!
+It needs at least [Synapse](https://github.com/matrix-org/synapse) v1.48.0 for all functions to work as expected!
 
 You get your server version with the request `/_synapse/admin/v1/server_version`.
 See also [Synapse version API](https://matrix-org.github.io/synapse/develop/admin_api/version_api.html).

src/synapse/dataProvider.js

@@ -69,7 +69,7 @@ const resourceMap = {
       return json.total_rooms;
     },
     delete: params => ({
-      endpoint: `/_synapse/admin/v1/rooms/${params.id}`,
+      endpoint: `/_synapse/admin/v2/rooms/${params.id}`,
       body: { block: false },
     }),
   },