Add a todo: a SymmetricMatrix should be used for dFdq

[[Imported from SVN: r9813]]

dune/gfe/localgeodesicfefunction.hh

@@ -473,6 +473,7 @@ evaluateDerivativeOfGradientWRTCoefficient(const Dune::FieldVector<ctype, dim>&
 
     AverageDistanceAssembler<TargetSpace> assembler(coefficients_, w);
 
+    /** \todo Use a symmetric matrix here */
     Dune::FieldMatrix<RT,embeddedDim,embeddedDim> dFdq(0);
     assembler.assembleEmbeddedHessian(q,dFdq);