don't crash on race with room members and initial composer render
don't crash on race with room members and initial composer render

not ideal, but for now this prevents a crash at startup
when a user-pill is persisted in local storage

matrix-org/matrix-react-sdk,matrix-org/matrix-react-sdk,matrix-org/matrix-react-sdk,matrix-org/matrix-react-sdk,matrix-org/matrix-react-sdk,matrix-org/matrix-react-sdk