The ornamental design for a controlunit, as shown and described.
FIG. 1 is a perspective view of the control unit.
FIG. 2 is a front elevation view thereof.
FIG. 3 is a right side elevation view thereof.
FIG. 4 is a left side elevation view thereof.
FIG. 5 is a bottom plan view thereof; and,
FIG. 6 is a top plan view thereof.
The broken lines in the drawings depict subject matter that forms no part of the claimed design. The rear view of the control unit forms no part of the claimed design.