The ornamental design for a lightsystem, as shown and described.
FIG. 1 is a top perspective view of a light system showing my new design;
FIG. 2 is a bottom perspective view thereof;
FIG. 3 is a top plan view thereof;
FIG. 4 is a bottom plan view thereof
FIG. 5 is a left side elevation view thereof;
FIG. 6 is a right side elevation view thereof;
FIG. 7 is a rear elevation view thereof;
FIG. 8 is a front elevation view thereof; and,
FIG. 9 is another top perspective view thereof, showing the light system in an installed configuration.
The broken lines in the drawing views represent unclaimed portions of a light system, which are included for the purpose of illustrating unclaimed environment only, and forms no part of the claimed design.