The ornamental design for a dispenser, as shown and described.
FIG. 1 is a perspective view of a dispenser showing my new design;
FIG. 2 is a front view thereof;
FIG. 3 is a rear view thereof;
FIG. 4 is a left side view thereof;
FIG. 5 is a right side view thereof;
FIG. 6 is a top view thereof;
FIG. 7 is a bottom view thereof;
FIG. 8 is a perspective view thereof, shown in use state; and,
FIG. 9 is a top view thereof, shown in use state.
The broken lines subject matter in FIGS. 8-9 are included for the purpose of illustrating unclaimed environment and form no part of the claimed design.