The ornamental design for a watersupplyadapter, as shown and described.
FIG. 1 is a top, front, left perspective view of a water supply adapter showing our new design;
FIG. 2 is a front view thereof;
FIG. 3 is a rear view thereof;
FIG. 4 is a left side view thereof;
FIG. 5 is a right side view thereof;
FIG. 6 is a top view thereof;
FIG. 7 is a bottom view thereof; and,
FIG. 8 is a top, front, left perspective view showing our new design of FIGS. 1-7 in an exemplary environment of a urinal.
The broken lines immediately adjacent to the shaded area define the bounds of the claimed design and form no part thereof. The broken lines depicting the remainder of the water supply adapter show features that form no part of the claimed design. The broken lines depicting exemplary environment in FIG. 8 form no part of the claimed design.