The ornamental design for an ashtray, as shown and described.
FIG. 1 is an upper perspective view of the ashtray showing my design;
FIG. 2 is a front elevation view thereof;
FIG. 3 is a back elevation view thereof;
FIG. 4 is a side elevation view thereof, wherein an opposite side elevation view is a mirror image of FIG. 3; and
FIG. 5 is a bottom plan view showing the broken lines indicating unclaimed portions of the ashtray;
FIG. 6 is a top plan view thereof; and,
FIG. 7 is another upper perspective view thereof, showing an opened configuration, wherein broken lines indicate internal structures as environment and form no part of the claimed design.
The broken lines indicate unclaimed subject matter of the design of the ashtray.