The ornamental design for a light-emitting diode, as shown and described here.
FIG. 1 is a perspective view of the light-emitting diode in accordance with my new design, showing an upper surface and side surfaces thereof as viewed from diagonally above;
FIG. 2 is a perspective view thereof, showing a bottom surface and side surfaces thereof as viewed from diagonally above;
FIG. 3 is a front elevational view thereof;
FIG. 4 is a rear elevational view thereof;
FIG. 5 is a top plan view thereof;
FIG. 6 is a bottom plan view thereof; and,
FIG. 7 is a left side view thereof (a right side view thereof is symmetrical to FIG. 7).