The ornamental design for modular stage leg bracing, as shown and described.
FIG. 1 is a top perspective view of a modular stage leg bracing embodying my design;
FIG. 2 is a side elevation view thereof; and,
FIG. 3 is a perspective view thereof.
The broken lines showing coupling fasteners, legs, leg sockets, and bracing connectors are for environmental purposes only and form no part of the claimed design.