Enable room version 4

src/client_server/capabilities.rs

 use crate::{database::DatabaseGuard, Result, Ruma};
-use ruma::{
-    api::client::discovery::get_capabilities::{
-        self, Capabilities, RoomVersionStability, RoomVersionsCapability,
-    },
+use ruma::api::client::discovery::get_capabilities::{
+    self, Capabilities, RoomVersionStability, RoomVersionsCapability,
 };
 use std::collections::BTreeMap;
 

src/database/globals.rs

@@ -151,7 +151,7 @@ pub fn load(
         // Supported and stable room versions
         let stable_room_versions = vec![RoomVersionId::V6];
         // Experimental, partially supported room versions
-        let unstable_room_versions = vec![RoomVersionId::V5];
+        let unstable_room_versions = vec![RoomVersionId::V4, RoomVersionId::V5];
 
         let s = Self {
             globals,

src/database/rooms.rs

@@ -1845,7 +1845,6 @@ pub fn build_and_append_pdu(
             })
             .transpose()?;
 
-
         // If there was no create event yet, assume we are creating a room with the default
         // version right now
         let room_version_id = create_event_content

src/server_server.rs

@@ -2592,9 +2592,9 @@ pub async fn create_join_event_template_route(
     acl_check(sender_servername, &body.room_id, &db)?;
 
     // TODO: Conduit does not implement restricted join rules yet, we always reject
-    let join_rules_event = db
-        .rooms
-        .room_state_get(&body.room_id, &StateEventType::RoomJoinRules, "")?;
+    let join_rules_event =
+        db.rooms
+            .room_state_get(&body.room_id, &StateEventType::RoomJoinRules, "")?;
 
     let join_rules_event_content: Option<RoomJoinRulesEventContent> = join_rules_event
         .as_ref()