The ornamental design for a bottlecap, substantially as shown.
FIG. 1 is a perspective view of a bottle cap with a non-monochromatic or reflective surface beneath a transparent domed top;
FIG. 2 is a front view of the bottle cap;
FIG. 3 is a rear view of the bottle cap;
FIG. 4 is a right side view of the bottle cap;
FIG. 5 is a left side view of the bottle cap;
FIG. 6 is a top view of the bottle cap; and,
FIG. 7 is a bottom view of the bottle cap.
Unless otherwise stated above, the broken line elements in all views are for illustrative and environmental purposes only and form no part of the claimed design.