The ornamental design for a sanitaryappliance, as shown and described.
FIG. 1 is a bottom, right, front perspective view of the sanitary appliance according to my design;
FIG. 2 is a front elevational view thereof, with the left side, right side and rear elevational views being identical thereto;
FIG. 3 is a top view thereof; and,
FIG. 4 is a bottom view thereof.
The broken lines showing the interior are included for the purpose of illustrating a portion of the appliance that forms no part of the claimed design.