The ornamental design for a mounting brackethangingplate, as shown and described.
FIG. 1 is a front perspective view of the panel portion for a mounting bracket hanging plate;
FIG. 2 is a front elevation view thereof;
FIG. 3 is a top plan view thereof;
FIG. 4 is a bottom plan view thereof;
FIG. 5 is a rear elevation view thereof;
FIG. 6 is a right elevation view thereof; and,
FIG. 7 is a left elevation view thereof.
The broken lines showing a mounting bracket hanging plate are included for the purpose of illustrating environment and form no part of the claimed design.