The ornamental design for a stringlight, as shown and described.
FIG. 1 is a perspective view of a string light showing my new design;
FIG. 2 is another perspective view thereof;
FIG. 3 is a front elevational view thereof;
FIG. 4 is a rear elevational view thereof;
FIG. 5 is a left side elevational view thereof;
FIG. 6 is a right side elevational view thereof;
FIG. 7 is a top plan view thereof;
FIG. 8 is a bottom plan view thereof; and,
FIG. 9 is an enlarged view of portion 9 shown in FIG. 1.
The evenly spaced broken lines are directed to environment. The interior broken line circle shapes seen in FIGS. 2 and 8 are boundary lines; the area within the boundary lines forms no part of the claimed design. The dot-dash broken lines in the drawings illustrate the enlargements of the design. None of the broken lines form no part of the claimed design.