The ornamental design for a projector, as shown and described.
FIG. 1 is a perspective view of a projector showing our new design;
FIG. 2 is a front elevational view thereof; and,
FIG. 3 is a partially enlarged perspective view thereof showing the claimed portion only.
The broken lines illustrating the unclaimed portions of the projector form no part of the claimed design. Dot-dash broken lines defining the boundaries of the claimed design form no part of the claimed design.