The ornamental design for a containercap, as shown and described.
FIG. 1 is a perspective view of a container cap showing our new design;
FIG. 2 is a side elevational view thereof;
FIG. 3 is a front elevational view thereof;
FIG. 4 is a back elevational view thereof; and,
FIG. 5 is a top plan view thereof.
The broken lines in the drawings are included for the purpose of illustrating features of the cap that form no part of the claimed design and also for illustrating an exemplary container on which the claim cap may be provided but which container forms no part of the claimed design. The bottom side is plain and unornamented and thus has not been illustrated or claimed.