The ornamental design for the bottle opener, as shown and described.
FIG. 1 is a top perspective view of the bottle opener showing my new design;
FIG. 2 is a front elevation view of the bottle opener of FIG. 1, the rear elevation view being a mirror image thereof;
FIG. 3 is a right side elevation view of the bottle opener of FIG. 1, the left side elevation view being a mirror image thereof;
FIG. 4 is a top view of the bottle opener of FIG. 1;
FIG. 5 is a bottom view of the bottle opener of FIG. 1; and,
FIG. 6 is a bottom perspective view of the bottle opener of FIG. 1.
The broken lines in the drawings are included for the purpose of illustrating unclaimed portions of the bottle opener and form no part of the claimed design.