The ornamental design for a ballnet, as shown and described.
FIG. 1 is a top, front, right perspective view of a ball net showing our new design in a position for use;
FIG. 2 is a front view thereof;
FIG. 3 is a rear view thereof;
FIG. 4 is a right side view thereof;
FIG. 5 is a left side view thereof;
FIG. 6 is a top view thereof; and,
FIG. 7 is a bottom view thereof.
The even-length broken lines within the shaded areas represent stitching which forms no part of the claimed design. The even-length broken lines showing the remainder of the ball net represent unclaimed subject matter and form no part of the claimed design. The uneven-length broken lines outside the shaded areas depict environmental structure in the form of a ball and form no part of the claimed design.