The ornamental design for a cartridge, as shown and described.
FIG. 1 is a perspective view of a cartridge, showing our new design;
FIG. 2 is a front view of the cartridge of FIG. 1;
FIG. 3 is a rear view of the cartridge of FIG. 1;
FIG. 4 is a left view of the cartridge of FIG. 1;
FIG. 5 is a right view of the cartridge of FIG. 1;
FIG. 6 is a top view of the cartridge of FIG. 1; and,
FIG. 7 is a bottom view of the cartridge of FIG. 1.
Dashed broken lines depict portions of the cartridge that form no part of the claimed design; dot-dash broken lines represent the boundary of the claimed design and form no part thereof.