[R-sig-Geo] leaflet problem

[Erich Subscriptions]

wien <- "http://maps1.wien.gv.at/basemap/bmapgrau/normal/google3857/{z}/{y}/{x}.png"
and 
addTiles(wien)

works,
but

wien <- "http://maps{s}.wien.gv.at/basemap/bmapgrau/normal/google3857/{z}/{y}/{x}.png"
and 
addTiles(wien,tileOptions(subdomain=“1234”))

does not work