The ornamental design for a door hinge, as shown and described.
FIG. 1 is a front elevational view showing my new design for a door hinge, it being understood that the shaft portion of the door hinge is shown broken away in this and other figure views to indicate that it is of indeterminate length;
FIG. 2 is a top plan view thereof, the bottom plan view being identical;
FIG. 3 is a right side elevational view;
FIG. 4 is a left side elevational view; and,
FIG. 5 is an elevational view taken on line 5—5 of FIG. 1.