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 bottom rear perspective view thereof;
FIG. 3 is a right end elevational view thereof; and
FIG. 4 is a top perspective view thereof in an open position, portions of
the carrying straps being broken away and omitted for convenience of
illustration.