The ornamental design for an electricalconnectorholder, as shown and described.
FIG. 1 is a perspective view of an electrical connector holder showing our new design;
FIG. 2 is a front view thereof;
FIG. 3 is a rear view thereof;
FIG. 4 is a top plan view thereof;
FIG. 5 is a right side view thereof; and,
FIG. 6 is a left side view thereof.
The broken lines illustrate portions of the electrical connector holder that form no part of the claimed design. The dash-dotted lines denote the boundary of the claim and form no part of the claimed design.