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 thereof;
FIG. 3 is a back view thereof;
FIG. 4 is a left side view thereof;
FIG. 5 is a right side view thereof;
FIG. 6 is a top view thereof;
FIG. 7 is a bottom view thereof; and,
FIG. 8 is a front perspective view of the handbag shown in FIG. 1 in an open position.
The evenly dashed broken lines depict portions of a handbag and form no part of the claim. The handbag is shown with symbolic break lines on the handles. The appearance of any portion of the article between the break lines forms no part of the claim.