The ornamental design for a handbag, as shown and described.
FIG. 1 is a first perspective view of a handbag showing my new design, with a strap shown in ghost for context;
FIG. 2 is a second perspective view thereof;
FIG. 3 is a front view of view thereof, where the strap is not shown for visual clarity;
FIG. 4 is a top view thereof, where the strap is not shown for visual clarity;
FIG. 5 is right side view thereof and the left side view is a mirror image of this view, where the strap is not shown for visual clarity;
FIG. 6 is a rear view thereof, where the strap is not shown for visual clarity; and,
FIG. 7 is a bottom view thereof, where the strap is not shown for visual clarity.
The dot-dashed broken lines showing a handbag strap are for the purposes of illustrating environment and form no part of the claimed design. The evenly spaced broken lines represent shading and are part of the claimed design.