The ornamental design for a retractableholder, as shown and described.
FIG. 1 is a perspective front, bottom and left side view showing the new design of a retractable holder according to the present invention; and,
FIG. 2 is a perspective back, bottom and right side view thereof.
The top surface has the same configuration as the other two side surfaces shown in FIGS. 1 and 2.
FIG. 1 shows the strap with a retractable portion withdrawn from the body; while FIG. 2 shows the strap with the retractable portion inserted into the body.