The ornamental design for a watchstrap, as shown and described.
FIG. 1 is a top front perspective view of a watch strap showing our new design;
FIG. 2 is a bottom rear perspective view thereof;
FIG. 3 is a top view thereof;
FIG. 4 is a bottom view thereof;
FIG. 5 is a right side view thereof;
FIG. 6 is a left side view thereof;
FIG. 7 is a front view thereof;
FIG. 8 is a rear view thereof;
FIG. 9 is a top perspective view of an alternate embodiment of a watch strap showing our new design;
FIG. 10 is a top view thereof;
FIG. 11 is a right side view thereof;
FIG. 12 is a left side view thereof;
FIG. 13 is a front view thereof; and,
FIG. 14 is a rear view thereof.
The broken lines immediately adjacent to the shaded areas represent the bounds of the claimed design and form no part thereof. The broken lines depicting the remainder of the watch strap show features that form no part of the claimed design.