We claim the ornamental design for a showerhead nozzle, as shown and described.
FIG. 1 is a left, front isometric view of a showerhead nozzle.
FIG. 2 is a right, front isometric view thereof.
FIG. 3 is a front elevation view thereof.
FIG. 4 is a rear elevation view thereof.
FIG. 5 is a left side elevation view thereof.
FIG. 6 is a right side elevation view thereof.
FIG. 7 is a top plan view thereof.
FIG. 8 is a bottom plan view thereof.
FIG. 9 is an enlarged fragmentary view thereof taken along detail line 9-9 of FIG. 2; and,
FIG. 10 is an enlarged fragmentary view thereof taken along detail line 10-10 of FIG. 3.
The broken line showing of the showerhead illustrates environment and forms no part of the claimed design. All other broken lines illustrate portions of the showerhead nozzle that form no part of the claimed design.