ENH: Added (commented) line for unity Lewis no in hsEqn

applications/solvers/combustion/reactingFoam/hsEqn.H

@@ -3,8 +3,8 @@
     (
         fvm::ddt(rho, hs)
       + mvConvection->fvmDiv(phi, hs)
-//      - fvm::laplacian(turbulence->alphaEff(), hs)
-      - fvm::laplacian(turbulence->muEff(), hs)  // unit lewis no.
+      - fvm::laplacian(turbulence->alphaEff(), hs)
+//      - fvm::laplacian(turbulence->muEff(), hs)  // unit lewis no.
      ==
         DpDt
       + chemistrySh