The ornamental design for handbag, as shown and described.
2.1 : Front view=back view
2.2 : Left view=right view
2.3 : Top
2.4 : Bottom
2.5 : Perspective
2.6 : Bag with removed strap and flap
2.7 : Bag with removed strap and flap
2.8 : Enlarged
2.9 : Enlarged
2.10 : Close up of strap attachment
The grayed out portions shown in broken lines depict portions of the handbag and form no part of the claim. The dashed stitching forms no part of the claim.