Clarify link.
# Restricting room membership based on space membership
-Draft join rule changes for [spaces](https://github.com/matrix-org/matrix-doc/pull/1772),
+Draft join rule changes for [MSC1772: spaces](https://github.com/matrix-org/matrix-doc/pull/1772),
this is meant to replaces the second half of [MSC2962](https://github.com/matrix-org/matrix-doc/pull/2962/).
A desirable feature is to give room admins the power to restrict membership of
