The ornamental design for a nightlight, as shown and described.
FIG. 1 illustrates a top right perspective view of a night light sitting atop its recharging base, according to present invention;
FIG. 2 illustrates another perspective view of the night light sitting atop its recharging base, this one from the left rear, according to the present invention;
FIG. 3 shows a rear view of the night light sitting atop its recharging base, according to the present invention;
FIG. 4 depicts a right side view of the night light sitting atop its recharging base, according to the present invention, a left side view is a mirror image of the right side view;
FIG. 5 shows a front view of the night light sitting atop its recharging base, according to the present invention; and,
FIG. 6 is a perspective view of the night light and its recharging base with the two units shown separated, according to the present invention.
The broken lines illustrated in the Figures represent portions of the night light which form no part of the claimed design.