The ornamental design for a conduitdredge, as shown and described.
FIG. 1 is a perspective view of a conduit dredge, showing my new design;
FIG. 2 is a front view thereof;
FIG. 3 is a rear view thereof;
FIG. 4 is a left side view thereof;
FIG. 5 is a right side view thereof;
FIG. 6 is a top view thereof; and,
FIG. 7 is a bottom view thereof.
In the drawings, the broken lines depict environmental subject matter only and form no part of the claimed design, and the chain lines with single dot depict boundaries between the claimed part and non-claimed part.