The ornamental design for a handbag, as shown and described.
FIG. 1 is a front perspective view of a handbag showing my new design;
FIG. 2 is a front view of the handbag shown in FIG. 1;
FIG. 3 is a back view of the handbag shown in FIG. 1;
FIG. 4 is a right side view of the handbag shown in FIG. 1;
FIG. 5 is a left side view of the handbag shown in FIG. 1;
FIG. 6 is a top view of the handbag shown in FIG. 1; and,
FIG. 7 is a bottom view of the handbag shown in FIG. 1.
The bolder broken lines showing a portion of the handbag opening, zipper pull and chain element are for the purposes of illustrating environment and form no part of the claimed design. The smaller spaced broken lines on the side panels and the strap pad represent stitching and is part of the claimed design.