BUG: wrong cellZone addressing in uniformityCellZone

Summary

The mean value, variance and volume fields for each zone are accessed using the wrong indices in objectiveUniformityCellZone.C

Possible fixes

For instance

      for (const label zI : zones_)                                               
      {                                                                           
          const cellZone& zoneI = mesh_.cellZones()[zI];                          
          scalarField VZone(V, zoneI);                                            
          vectorField UZone(U.primitiveField(), zoneI);                           
          volZone_[zI] = gSum(VZone);                                             
          UMean_[zI] = gSum(UZone*VZone)/volZone_[zI];                            
          UVar_[zI] = gSum(magSqr(UZone - UMean_[zI])*VZone)/volZone_[zI];        
                                                                                  
          J_ += 0.5*UVar_[zI];                                                    
      } 

should become

      forAll(zones_, zI)                                               
      {                                                                           
          const cellZone& zoneI = mesh_.cellZones()[zones_[zI]];                          
          scalarField VZone(V, zoneI);                                            
          vectorField UZone(U.primitiveField(), zoneI);                           
          volZone_[zI] = gSum(VZone);                                             
          UMean_[zI] = gSum(UZone*VZone)/volZone_[zI];                            
          UVar_[zI] = gSum(magSqr(UZone - UMean_[zI])*VZone)/volZone_[zI];        
                                                                                  
          J_ += 0.5*UVar_[zI];                                                    
      }