forceCoeffs: Removed duplicate header writing

Patch contributed by Bruno Santos
Resolves bug-report http://bugs.openfoam.org/view.php?id=2216

src/functionObjects/forces/forceCoeffs/forceCoeffs.C

@@ -60,9 +60,6 @@ void Foam::functionObjects::forceCoeffs::writeFileHeader(const label i)
         writeTabbed(file(i), "Cl");
         writeTabbed(file(i), "Cl(f)");
         writeTabbed(file(i), "Cl(r)");
-        file(i)
-            << tab << "Cm" << tab << "Cd" << tab << "Cl" << tab << "Cl(f)"
-            << tab << "Cl(r)";
     }
     else if (i == 1)
     {