The ornamental design for a cargocontainer, as shown and described.
FIG. 1 is a front, top, and right side perspective view of the cargo container, showing the new design;
FIG. 2 is a front side elevational view thereof;
FIG. 3 is a rear side elevational view thereof;
FIG. 4 is a left side elevational view thereof;
FIG. 5 is a right side elevational view thereof;
FIG. 6 is a top plan view thereof; and,
FIG. 7 is a bottom plan view thereof.
The ornamental design which is claimed is shown in solid lines in the drawings. Any broken lines in the drawings are for illustrative purposes only and form no part of the claimed design.