The ornamental design for a phototherapylamp, as shown and described.
FIG. 1 is a front and right perspective view of a phototherapy lamp, showing my design;
FIG. 2 is a rear and right perspective 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; and,
FIG. 8 is a bottom plan view thereof.
The broken lines in FIGS. 1 and 3 illustrate a portion of the phototherapy lamp that forms no part of the claimed design; the broken lines form no part of the claimed design.