wrong sign of source.m_flow_in in AixLib.Fluid.DistrictHeatingCooling.Demands.OpenLoop.VarTSupplyDpBypass

[j-zipplies]

Describe the bug Within AixLib.Fluid.DistrictHeatingCooling.Demands.OpenLoop.VarTSupplyDpBypass the connector source.m_flow_in is connected to changeSing.y (the negative mass flow signal = inflow) instead of smoothMax.y (which would be the correct outflow from the model). This wrong connection lets this load model "consume" water from both, flow and return line of the pipe network.

To Reproduce Check the model itself or simulation results from AixLib.Fluid.DistrictHeatingCooling.Demands.Examples.OpenLoopVarTSupplyDpBypass (flow velocity in pipeReturn is negative)