The ornamental design for a connector, as shown and described.
FIG. 1 is a front, bottom, right perspective view of a connector showing our new design;
FIG. 2 is a front, top, right perspective view thereof; and,
FIG. 3 is a front elevational view thereof.
The broken lines illustrating the unclaimed portions of the connector form no part of the claimed design. Dot-dash broken lines define the boundaries of, but not included in, the claimed design.