one or more halogens selected from F, Cl and Br, provided that at least one of R1 and R2 is a halogen substituted alkyl, cycloalkyl or cycloalkylalkyl and provided that there is no halogen substituent on the carbon directly attached to the nitrogen; and X, m, Y, n and R3 are as described in the specification; and the pharmaceutically-acceptable acid-addition salts thereof.