The ornamental design for a currentsensor, as shown and described.
FIG. 1 is a perspective view of the top, front and right side of a current sensor showing our new design of an embodiment;
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;
FIG. 6 is a left side view thereof; and,
FIG. 7 is a perspective reference view of usage.
The broken line showing of structural features is included for the purpose of illustrating non-claimed subject matter and forms no part of the claimed design.