The ornamental design for a shower handle, as shown and described.
FIG. 1 is a front perspective view of a shower handle showing my new design;
FIG. 2 is a front view thereof;
FIG. 3 is a rear view thereof;
FIG. 4 is a right side view thereof;
FIG. 5 is a left side view thereof;
FIG. 6 is a top view thereof; and,
FIG. 7 is a bottom view thereof.
The broken line immediately adjacent to the photographic area defines the bounds of the claimed design and forms no part thereof. The unshaded area within the broken lines forms no part of the claimed design.