We claim the ornamental design for a watch strap, as shown and described.
FIG. 1 is a top perspective view of a watch strap, showing our new design;
FIG. 2 is a bottom perspective view thereof;
FIG. 3 is a top plan view thereof;
FIG. 4 is a bottom plan view thereof;
FIG. 5 is a left elevational view thereof;
FIG. 6 is a right elevational view thereof;
FIG. 7 is a back elevational view thereof; and,
FIG. 8 is a front elevational view thereof.
The broken lines are for the purpose of illustrating portions of the article and form no part of the claimed design.
The watch strap is shown with a symbolic break in its length. The appearance of any portion of the article between the break lines forms no part of the claimed design.