The ornamental design for a “padlock vault”, as shown and described.
FIG. 1 is a rear perspective view of the padlock vault;
FIG. 2 is a front view of the padlock vault;
FIG. 3 is a rear view of the padlock vault;
FIG. 4 is a top view of the padlock vault;
FIG. 5 is a bottom view of the padlock vault;
FIG. 6 is a right side view of the padlock vault;
FIG. 7 is a left side view of the padlock vault; and,
FIG. 8 is a front perspective view of the first embodiment of the padlock vault, the broken line showing of the padlock is for illustrative purposes only and form no part of the claimed design.