tutorials/compressible/rhoSimpleFoam/squareBend: Stabilize by further relaxing e

Patch contributed by Mattijs Janssens
http://bugs.openfoam.org/view.php?id=2382

tutorials/compressible/rhoSimpleFoam/squareBend/system/fvSolution

@@ -66,7 +66,7 @@ relaxationFactors
     {
         p               1;
         U               0.9;
-        e               0.9;
+        e               0.8;
         k               0.9;
         epsilon         0.9;
     }