The ornamental design for the light line, as shown and described.
FIG. 1 shows a front perspective view of a light line;
FIG. 2 shows a front view of the light line of FIG. 1;
FIG. 3 shows a rear view of the light line of FIG. 1;
FIG. 4 shows a right side view of the light line of FIG. 1;
FIG. 5 shows a left side view of the light line of FIG. 1;
FIG. 6 shows a top view of the light line of FIG. 1; and,
FIG. 7 shows a bottom view of the light line of FIG. 1.
The broken lines in the drawings depict portions of the light line that form no part of the claimed design.
The light line is shown with a symbolic break in its length. The appearance of any portion of the article between the break lines forms no part of the claimed design.