The ornamental design for a soapmoldingdish, as shown and described.
FIG. 1 is a perspective view of a soap molding dish showing our new design, the dish being shown in an opened position, and the broken-line disclosure being understood to represent portions of the dish which form no part of the claimed design;
FIG. 2 is a left side elevational view thereof, in a closed position;
FIG. 3 is a right side elevational view thereof, in a closed position;
FIG. 4 is a top plan view thereof, in a closed position; and,
FIG. 5 is a bottom plan view thereof, in a closed position.