The ornamental design for a wriststrap for a camera, as shown and described.
FIG. 1 is a perspective view of the wrist strap for a camera of the invention shown in use with the hand of a user and an associated camera shown in dotted lines as not forming a portion of the present invention;
FIG. 2 is an isolated, perspective view of the wrist strap for a camera of FIG. 1;
FIG. 3 is an end view of the wrist strap for a camera of the invention, taken from the left end of the strap as presented in the view of FIG. 2;
FIG. 4 is an end view of the wrist strap for a camera of the invention, taken from the right end of the strap as presented in the view of FIG. 2;
FIG. 5 is a side view of the wrist strap for a camera of the invention, taken from the left side of the view as presented in FIG. 2;
FIG. 6 is a top view of the wrist strap for a camera of the invention; and,
FIG. 7 is a bottom view of the wrist strap for a camera of the invention.
The dashed lines representing stitching do form part of the claimed design.