The ornamental design for a cartridge, as shown and described.
FIG. 1 is a perspective view of the cartridge showing of our new and ornamental design;
FIG. 2 is an alternate perspective view thereof;
FIG. 3 is a side view thereof;
FIG. 4 is a front view thereof;
FIG. 5 is top view thereof; and,
FIG. 6 is a bottom view thereof.
The portions of the cartridge shown in broken lines shown in the figures attached hereto form no part of the claimed design. The unshaded surfaces immediately adjacent to the broken lines depict portions of the cartridge that form no part of the claimed design.