Support for petsc3.5 (fix compilation has they change the aruments of
KSPSetOperator method). Not one hundred purcent sure that the fix is
equivelent to the options set before 


git-svn-id: https://geuz.org/svn/gmsh/trunk@19402 59c8cabf-10d6-4a28-b43f-3936b85956c4
Fix the fix of PETSc3.5


git-svn-id: https://geuz.org/svn/gmsh/trunk@19403 59c8cabf-10d6-4a28-b43f-3936b85956c4