The ornamental design for an ledhighmastlight, as shown and described.
FIG. 1 is a front view of a first embodiment of an LED high mast light showing my design;
FIG. 2 is a back view of the first embodiment thereof;
FIG. 3 is a left side view of the first embodiment thereof;
FIG. 4 is a right side view of the first embodiment thereof;
FIG. 5 is a top view of the first embodiment thereof;
FIG. 6 is a bottom view of the first embodiment thereof;
FIG. 7 is a first perspective view of the first embodiment thereof; and,
FIG. 8 is a second perspective view of the first embodiment thereof.
The broken lines shown in the drawings depict portions of the LED high mast light in which the design is embodied that form no part of the claimed design.