The ornamental design for a handbag, as shown and described.
FIG. 1 is a perspective view of a handbag;
FIG. 2 is a front view of a handbag;
FIG. 3 is a rear view of a handbag;
FIG. 4 is a left side view of a handbag;
FIG. 5 is a right side view of a handbag;
FIG. 6 is a top view of a handbag;
FIG. 7 is a bottom view of a handbag; and,
FIG. 8 is a perspective open interior view of a handbag.
The dotted lines shown in the figures represent stitching. The criss-cross pattern applied to specific surface areas is intended to represent different fabric material from the rest of the handbag.
The broken lines shown in the figures are included for the purpose of illustrating the environment in which the design is used and form no part of the claimed design.