BUG: Fixed crash when there is no GLX support in X server.
BUG: Fixed crash when there is no GLX support in X server.

aashish24/VTK-old,SimVascular/VTK,keithroe/vtkoptix,Wuteyan/VTK,spthaolt/VTK,ashray/VTK-EVM,naucoin/VTKSlicerWidgets,jmerkow/VTK,spthaolt/VTK,jmerkow/VTK,cjh1/VTK,cjh1/VTK,cjh1/VTK,sumedhasingla/VTK,sankhesh/VTK,cjh1/VTK,demarle/VTK,SimVascular/VTK,jmerkow/VTK,hendradarwin/VTK,collects/VTK,mspark93/VTK,msmolens/VTK,sumedhasingla/VTK,arnaudgelas/VTK,sgh/vtk,gram526/VTK,cjh1/VTK,berendkleinhaneveld/VTK,daviddoria/PointGraphsPhase1,biddisco/VTK,spthaolt/VTK,keithroe/vtkoptix,jeffbaumes/jeffbaumes-vtk,demarle/VTK,sankhesh/VTK,arnaudgelas/VTK,sgh/vtk,mspark93/VTK,sumedhasingla/VTK,mspark93/VTK,gram526/VTK,naucoin/VTKSlicerWidgets,gram526/VTK,berendkleinhaneveld/VTK,Wuteyan/VTK,demarle/VTK,candy7393/VTK,johnkit/vtk-dev,candy7393/VTK,naucoin/VTKSlicerWidgets,johnkit/vtk-dev,msmolens/VTK,johnkit/vtk-dev,sgh/vtk,SimVascular/VTK,keithroe/vtkoptix,keithroe/vtkoptix,msmolens/VTK,ashray/VTK-EVM,sumedhasingla/VTK,aashish24/VTK-old,aashish24/VTK-old,sumedhasingla/VTK,jeffbaumes/jeffbaumes-vtk,SimVascular/VTK,sankhesh/VTK,hendradarwin/VTK,cjh1/VTK,naucoin/VTKSlicerWidgets,collects/VTK,berendkleinhaneveld/VTK,collects/VTK,biddisco/VTK,hendradarwin/VTK,demarle/VTK,mspark93/VTK,jmerkow/VTK,berendkleinhaneveld/VTK,jmerkow/VTK,ashray/VTK-EVM,arnaudgelas/VTK,SimVascular/VTK,Wuteyan/VTK,jeffbaumes/jeffbaumes-vtk,keithroe/vtkoptix,hendradarwin/VTK,candy7393/VTK,naucoin/VTKSlicerWidgets,sumedhasingla/VTK,jmerkow/VTK,berendkleinhaneveld/VTK,sgh/vtk,candy7393/VTK,collects/VTK,daviddoria/PointGraphsPhase1,berendkleinhaneveld/VTK,mspark93/VTK,gram526/VTK,arnaudgelas/VTK,keithroe/vtkoptix,biddisco/VTK,jmerkow/VTK,aashish24/VTK-old,johnkit/vtk-dev,spthaolt/VTK,biddisco/VTK,mspark93/VTK,msmolens/VTK,msmolens/VTK,gram526/VTK,candy7393/VTK,spthaolt/VTK,sankhesh/VTK,sankhesh/VTK,candy7393/VTK,mspark93/VTK,gram526/VTK,ashray/VTK-EVM,demarle/VTK,gram526/VTK,gram526/VTK,keithroe/vtkoptix,sgh/vtk,candy7393/VTK,ashray/VTK-EVM,biddisco/VTK,candy7393/VTK,daviddoria/PointGraphsPhase1,ashray/VTK-EVM,jeffbaumes/jeffbaumes-vtk,daviddoria/PointGraphsPhase1,johnkit/vtk-dev,sankhesh/VTK,hendradarwin/VTK,spthaolt/VTK,biddisco/VTK,sgh/vtk,spthaolt/VTK,arnaudgelas/VTK,keithroe/vtkoptix,aashish24/VTK-old,jmerkow/VTK,demarle/VTK,ashray/VTK-EVM,sankhesh/VTK,sumedhasingla/VTK,sumedhasingla/VTK,hendradarwin/VTK,SimVascular/VTK,aashish24/VTK-old,daviddoria/PointGraphsPhase1,demarle/VTK,jeffbaumes/jeffbaumes-vtk,Wuteyan/VTK,johnkit/vtk-dev,biddisco/VTK,msmolens/VTK,Wuteyan/VTK,hendradarwin/VTK,demarle/VTK,collects/VTK,berendkleinhaneveld/VTK,johnkit/vtk-dev,msmolens/VTK,mspark93/VTK,SimVascular/VTK,Wuteyan/VTK,arnaudgelas/VTK,Wuteyan/VTK,SimVascular/VTK,sankhesh/VTK,collects/VTK,daviddoria/PointGraphsPhase1,msmolens/VTK,ashray/VTK-EVM,jeffbaumes/jeffbaumes-vtk,naucoin/VTKSlicerWidgets