Make room version 5 the default room version.
As per [MSC2334](https://github.com/matrix-org/matrix-doc/pull/2334)
@@ -540,7 +540,7 @@ some other reason. Versions can switch between stable and unstable periodically
for a variety of reasons, including discovered security vulnerabilities and age.
Clients should not ask room administrators to upgrade their rooms if the room is
-running a stable version. Servers SHOULD use room version 4 as the default room
+running a stable version. Servers SHOULD use room version 5 as the default room
version when creating new rooms.
The available room versions are:
