make sure room.tags is always a valid object so no crashes happen later on
make sure room.tags is always a valid object so no crashes happen later on

matrix-org/matrix-js-sdk,matrix-org/matrix-js-sdk,krombel/matrix-js-sdk,matrix-org/matrix-js-sdk,krombel/matrix-js-sdk,matrix-org/matrix-js-sdk,krombel/matrix-js-sdk