I claim the ornamental design for a straddle mount connector, as shown and described.
FIG. 1 is a rear perspective view of a straddle mount connector showing my new design;
FIG. 2 is a top plan view thereof;
FIG. 3 is a bottom plan view thereof;
FIG. 4 is a front plan view thereof;
FIG. 5 is a rear plan view thereof;
FIG. 6 is a left side view thereof; and,
FIG. 7 is a right side view thereof.
The broken line portion of the figures is included to show unclaimed subject matter only and forms no part of the claimed design. The dash-dot line represents the boundary of the claim design.