The ornamental design for a mountingbracket, as shown and described.
FIG. 1 is a perspective view of a mounting bracket showing our new design;
FIG. 2 is a top view of the mounting bracket of FIG. 1;
FIG. 3 is a right-side view of the mounting bracket of FIG. 1 with the opposite side being a mirror image;
FIG. 4 is a bottom view of the mounting bracket of FIG. 1;
FIG. 5 is a rear view of the mounting bracket of FIG. 1; and,
FIG. 6 is a front view of the mounting bracket of FIG. 1.
The broken lines and areas within the broken lines where contour shading is not shown illustrate portions of the mounting bracket that form no part of the claimed design.