The ornamental design for a projector, as shown and described.
FIG. 1 is a front, top, and right-side perspective view of the projector with the lens cover open;
FIG. 2 is a front, top, and left-side perspective view of the projector with the lens cover closed;
FIG. 3 is a front view of the projector with the lens cover open;
FIG. 4 is a rear view of the projector;
FIG. 5 is a left-side view of the projector;
FIG. 6 is a right-side view of the projector;
FIG. 7 is a top view of the projector with the lens cover open; and,
FIG. 8 is a bottom view of the projector.
The broken lines shown portions of the projector is included for the purpose of illustrating environmental structure and forms no part of the claimed design.