The ornamental design for a displaycabinet, as shown and described.
FIG. 1 is a perspective view of a display cabinet in accordance with the present invention;
FIG. 2 is a front plan view of the display cabinet showing, in broken lines, a portable fireplace displayed thereon for illustrative purposes only and therefore forming no part of the claimed design;
FIG. 3 is a rear elevation view of the display cabinet with the portable fireplace shown in broken lines;
FIG. 4 is a top plan view of the display cabinet;
FIG. 5 is a bottom plan view of the display cabinet;
FIG. 6 is a right elevation view of the display cabinet with the portable fireplace shown in broken lines; and,
FIG. 7 is a left elevation view of the display cabinet with the portable fireplace shown in broken lines.