The ornamental design for a shoe upper, as shown and described.
FIG. 1 is a perspective view of a shoe upper according to the present invention;
FIG. 2 is a top view of the shoe upper of FIG. 1;
FIG. 3 is a right side view of the shoe upper of FIG. 1;
FIG. 4 is a left side view of the shoe upper of FIG. 1; and,
FIG. 5 is a front view of the shoe upper of FIG. 1.
The broken lines in the figures merely illustrate the environment for the shoe upper of the present design and therefore form no part of the claimed design.