COMP: Add execption for vtkJSONWriter
COMP: Add execption for vtkJSONWriter

The TestSetGet.tcl scrip is failing on platforms that have
Module_vtkIOGeoJSON:BOOL=ON
The method GetOutputStdString is only valid when WriteToOutputString
is on. This patch adds GetOutputStdString to the exceptions.

Change-Id: I149f34c0a9d769ad963db99c80dce3469b6a93e3

jmerkow/VTK,keithroe/vtkoptix,keithroe/vtkoptix,demarle/VTK,jmerkow/VTK,mspark93/VTK,msmolens/VTK,gram526/VTK,mspark93/VTK,candy7393/VTK,candy7393/VTK,msmolens/VTK,sumedhasingla/VTK,ashray/VTK-EVM,candy7393/VTK,mspark93/VTK,sumedhasingla/VTK,hendradarwin/VTK,ashray/VTK-EVM,demarle/VTK,keithroe/vtkoptix,sankhesh/VTK,msmolens/VTK,mspark93/VTK,sankhesh/VTK,johnkit/vtk-dev,gram526/VTK,candy7393/VTK,keithroe/vtkoptix,johnkit/vtk-dev,sankhesh/VTK,msmolens/VTK,candy7393/VTK,gram526/VTK,jmerkow/VTK,msmolens/VTK,SimVascular/VTK,gram526/VTK,keithroe/vtkoptix,johnkit/vtk-dev,mspark93/VTK,hendradarwin/VTK,ashray/VTK-EVM,keithroe/vtkoptix,demarle/VTK,msmolens/VTK,SimVascular/VTK,johnkit/vtk-dev,johnkit/vtk-dev,demarle/VTK,sankhesh/VTK,ashray/VTK-EVM,demarle/VTK,SimVascular/VTK,gram526/VTK,mspark93/VTK,sumedhasingla/VTK,jmerkow/VTK,keithroe/vtkoptix,sankhesh/VTK,candy7393/VTK,johnkit/vtk-dev,sumedhasingla/VTK,hendradarwin/VTK,mspark93/VTK,SimVascular/VTK,demarle/VTK,SimVascular/VTK,hendradarwin/VTK,sankhesh/VTK,SimVascular/VTK,ashray/VTK-EVM,demarle/VTK,candy7393/VTK,gram526/VTK,sankhesh/VTK,ashray/VTK-EVM,hendradarwin/VTK,sumedhasingla/VTK,jmerkow/VTK,jmerkow/VTK,ashray/VTK-EVM,johnkit/vtk-dev,msmolens/VTK,msmolens/VTK,SimVascular/VTK,sumedhasingla/VTK,mspark93/VTK,keithroe/vtkoptix,jmerkow/VTK,SimVascular/VTK,gram526/VTK,candy7393/VTK,ashray/VTK-EVM,sumedhasingla/VTK,hendradarwin/VTK,hendradarwin/VTK,gram526/VTK,sumedhasingla/VTK,jmerkow/VTK,sankhesh/VTK,demarle/VTK