The ornamental design for a shoe upper, as shown and described.
FIG. 1 is a rear perspective view of a shoe upper showing my new design;
FIG. 2 is a side view thereof;
FIG. 3 is a second side view thereof; and,
FIG. 4 is a rear view thereof.
The broken lines immediately adjacent to the shaded area represent unclaimed boundaries of the design. The contrast in shading represents a contrast in appearance only and does not represent any particular color, material, texture or finish. The broken lines showing the remainder of the shoe represent unclaimed subject matter and form no part of the claimed design.