message: add final return for clarity
diff: @@ -163,6 +163,7 @@ function createSelfRoomMembershipAction(matrixClient, membershipEvent, member, o
  if (member.userId === matrixClient.getUserId()) {
  return { action: 'MatrixActions.Room.selfMembership', member };
  }
  + return null;
  }
  /**
  