The ornamental design for a loadingrack, as shown and described.
FIG. 1 is an isometric view of a loading rack showing my new design;
FIG. 2 is a front elevational view thereof, with the rear being the same;
FIG. 3 is a right side elevational view thereof, with the left side elevational view being the same;
FIG. 4 is a top plan view thereof; and,
FIG. 5 is a bottom plan view thereof.
The broken lines shown in the figures are included for the purpose of illustrating portions of the loading rack and form no part of the claimed design.