The ornamental design for a shoe upper, as shown and described.
FIG. 1 is a front perspective view of a shoe upper showing my new design;
FIG. 2 is a side view thereof; and,
FIG. 3 is a second side view thereof.
The broken line showing of four genuinely horizontal grooves on the strap are for environmental purposes only and form no part of the claimed design. The single broken line adjacent to the bottom of the strap represents unclaimed stitching and forms no part of the claimed design. The broken lines showing the remainder of the shoe are for environmental purposes only and form no part of the claimed design.