The ornamental design for a dispenser, as shown and described.
FIG. 1 is front perspective view of our dispenser;
FIG. 2 is an elevation view of the front thereof;
FIG. 3 is an elevation view of the rear thereof;
FIG. 4 is a plan view of the top thereof;
FIG. 5 is a plan view of the bottom thereof;
FIG. 6 is an elevation view of the right side thereof; and,
FIG. 7 is an elevation view of the left side thereof.
The broken line showing of the elements on the front of the dispenser is included for the purpose of illustrating and forms no part of the claimed design.