The ornamental design for a foldable displaystand, substantially as shown and described.
FIG. 1 is a perspective view of a foldable display stand according to the present invention;
FIG. 2 is a side elevation view of the foldable display stand shown in FIG. 1;
FIG. 3 is an elevation view of a side of the foldable display stand that is generally perpendicular to the side view of the foldable display stand shown in FIG. 2;
FIG. 4 is a top plan view of the foldable display stand shown in FIG. 1; and,
FIG. 5 is a bottom plan view of the foldable display stand shown in FIG. 1.
The broken lines in the drawings are for illustrative purposes only and form no part of the claimed design.