The ornamental design for a connector, as shown and described.
FIG. 1 is a front perspective view of a connector showing our new design;
FIG. 2 is a front view thereof;
FIG. 3 is a top view thereof;
FIG. 4 is a bottom view thereof;
FIG. 5 is a left side view thereof;
FIG. 6 is a right side view thereof; and,
FIG. 7 is a rear view thereof.
The broken-lines immediately adjacent the shaded areas represent the bounds of the claimed design, while all other broken lines represent environmental structure for illustrative purposes only and form no part of the claimed design.