The ornamental design for a nailtoolholder, as shown and described.
FIG. 1 is a perspective view of a nail tool holder;
FIG. 2 is a front elevational view thereof;
FIG. 3 is a rear elevational view thereof;
FIG. 4 is a left side elevational view thereof;
FIG. 5 is a right side elevational view thereof;
FIG. 6 is a top plan view thereof; and,
FIG. 7 is a bottom plan view thereof.
The broken line showing of the nail clipper is included for the purpose of illustrating the environment of the nail tool holder and forms no part of the claimed design.