The ornamental design for a diaperbag, as shown and described.
FIG. 1 is a front perspective view of a diaper bag according to the present invention;
FIG. 2 is face on front view thereof;
FIG. 3 is a right-side edge-on view thereof;
FIG. 4 is a left-side edge-on view thereof;
FIG. 5 is back view thereof;
FIG. 6 is a top-down edge-on view thereof; and,
FIG. 7 is a bottom-up edge-on view thereof.
Any broken lines are for illustrative purposes only and form no part of the claimed design. Any surface shading illustrated in the drawings is provided merely to highlight the contour of the design; it is not intended to be illustrative of texture or gloss.