Compounds of formula (I)
as well as pharmaceutically acceptable salts and esters thereof, wherein R1 to R3 have the significance given in claim 1 and which can be used in the form of pharmaceutical compositions.
Compounds of formula (I) as well as pharmaceutically acceptable salts and esters thereof, wherein R1 to R3 have the significance given in claim 1 and which can be used in the form of pharmaceutical compositions.