add index constraints for gurobi proto solve
add index constraints for gurobi proto solve

or-tools/or-tools,google/or-tools,google/or-tools,google/or-tools,or-tools/or-tools,google/or-tools,or-tools/or-tools,or-tools/or-tools,or-tools/or-tools,google/or-tools,google/or-tools,or-tools/or-tools