The ornamental design for spray dispenser, as shown and described.
FIG. 1 is a right side view of spray dispenser, showing the new design, where the right side view is a mirror image of the left side view;
FIG. 2 is a front view thereof;
FIG. 3 is a top view thereof;
FIG. 4 is a rear view thereof; and,
FIG. 5 is a bottom view thereof, where broken lines in the drawings indicate the boundary of the claimed design and form no part of the claimed design.