The ornamental design for a handbag, as shown and described.
FIG. 1 is a front and top perspective view of a handbag, showing my new design;
FIG. 2 is a rear and bottom perspective view thereof;
FIG. 3 is a front elevational view thereof;
FIG. 4 is a rear elevational view thereof;
FIG. 5 is a left side elevational view thereof;
FIG. 6 is a right side elevational view thereof;
FIG. 7 is a top plan view thereof;
FIG. 8 is a bottom plan view thereof; and,
FIG. 9 is an enlarged detail view of area 9 circumscribed within FIG. 1.
The broken lines in the figures illustrate portions of the a handbag that form no part of the claimed design. The dot dash dot broken lines in FIGS. 1 and 9 depict the boundaries of the enlarged detail views and form no part of the claimed design.