[VTK-4816] Ignore TimeoutException wrapped in IOException
[VTK-4816] Ignore TimeoutException wrapped in IOException

Ignore TimeoutExceptions wrapped in IOExceptions in
VTKServlet#handleError, as they are most likely caused by premature
client disconnect. Instead of logging stack trace to error log, just
log as info message to debug log.

vtkio/vtk,vtkio/vtk,vtkio/vtk,vtkio/vtk,vtkio/vtk,vtkio/vtk,vtkio/vtk,vtkio/vtk