The ornamental design for a handbag, as shown and described.
FIG. 1 is a front perspective view of the handbag shown in FIG. 1;
FIG. 2 is a front view of the handbag in FIG. 1;
FIG. 3 is a rear view of the handbag in FIG. 1;
FIG. 4 is a left side view of the handbag in FIG. 1;
FIG. 5 is a right side view of the handbag in FIG. 1;
FIG. 6 is a top view of the handbag in FIG. 1; and,
FIG. 7 is a bottom view of the handbag in FIG. 1.
The broken line showing of the metal plaque, hardware, stitching, fringe, weaving, handles and body of the bag is for the purposes of illustrating environment and forms no part of the claimed design.