The ornamental design for a storagebox for gamecard, as shown and described.
FIG. 1 is a perspective view of a storage box for game card showing my new design;
FIG. 2 is a front view thereof;
FIG. 3 is a back view thereof;
FIG. 4 is a left side view thereof;
FIG. 5 is a right side view thereof;
FIG. 6 is a top view thereof;
FIG. 7 is a bottom view thereof; and,
FIG. 8 is a perspective view of another state of the storage box for game card thereof.
The broken lines shown in the drawings depict portions of the storage box for game card in which the design is embodied that form no part of the claimed design.