ENH: Moved call to constrain to after equation relaxation

applications/solvers/incompressible/simpleFoam/MRFSimpleFoam/UEqn.H

@@ -10,8 +10,8 @@
 
     mrfZones.addCoriolis(UEqn());
 
-    sources.constrain(UEqn());
-
     UEqn().relax();
 
+    sources.constrain(UEqn());
+
     solve(UEqn() == -fvc::grad(p));