Fixed a memory leak in the lagrangian enforced preconditioner.
 modified:   src/navier_stokes/lagrange_enforced_flow_preconditioner.h

git-svn-id: svn+ssh://maths1/home/svn-oomphlib/public/trunk@734 595e1d82-adf1-4282-bac7-b6073fa2ca8e