The ornamental design for a projector, as shown and described.
FIG. 1 is a slightly reduced bottom perspective view of a projector showing my design;
FIG. 2 is a slightly reduced top perspective view thereof;
FIG. 3 is a front view thereof;
FIG. 4 is a rear view thereof
FIG. 5 is a left side view thereof;
FIG. 6 is a right side view thereof;
FIG. 7 is a top view thereof; and,
FIG. 8 is a bottom view thereof.
The broken line immediately adjacent the claimed areas represent the bounds of the claimed design while all other broken lines are unclaimed portions of the claimed design and form no part thereof.