Fix memory leas in vtkCamera::ShallowCopy()

  vtkCamera::ShallowCopy() did not correctly release previously allocated
  transforms before shallow-copying. Fixed that.

Change-Id: I33e29c92589f7642c006bb45d4179b50a39e7bae
Merge topic 'fix_vtkCamera_leaks' into master

4c97a574 Fix memory leas in vtkCamera::ShallowCopy()