The ornamental design for a labelprintercassette, as shown and described.
FIG. 1 is a front perspective view of a label printer cassette of the present disclosure;
FIG. 2 is a rear perspective view thereof;
FIG. 3 is a front elevational view thereof;
FIG. 4 is a rear elevational view thereof;
FIG. 5 is a left-side elevational view thereof;
FIG. 6 is a right-side elevational view thereof;
FIG. 7 is a top plan view thereof; and,
FIG. 8 is a bottom plan view thereof.
The broken lines shown in the drawings are for the purpose of illustrating portions of the label printer cassette that form no part of the claimed design.