The ornamental design for a distributionboard, as shown and described.
FIG. 1. is a front, right, and top perspective view of a distribution board showing our new design;
FIG. 2. is a rear left, and top perspective view thereof;
FIG. 3. is a front elevation view thereof;
FIG. 4. is a rear elevation view thereof;
FIG. 5. is a left elevation side view thereof;
FIG. 6. is a right elevation side view thereof;
FIG. 7. is a top plan view thereof; and,
FIG. 8. is a bottom plan view thereof.
The broken lines immediately adjacent the shaded areas represent the bounds of the claimed design while all other broken lines on the unshaded bottom surface are directed to environment; the broken lines form no part of the claimed design.