The ornamental design for a camera, as shown and described.
FIG. 1 is a perspective view of a camera showing our new design;
FIG. 2 is another perspective view thereof;
FIG. 3 is another perspective view thereof;
FIG. 4 is another perspective view thereof;
FIG. 5 is a front view thereof;
FIG. 6 is a rear view thereof;
FIG. 7 is a left side view thereof;
FIG. 8 is a right side view thereof;
FIG. 9 is a top view thereof; and,
FIG. 10 is a bottom view thereof.
The dashed broken lines illustrate portions of the article that form no part of the claimed design. The dot-dash broken lines represent the boundaries of the claimed design, and form no part thereof.