Added a check if multiwidget is NULL: this avoid crashes of the program.
Added a check if multiwidget is NULL: this avoid crashes of the program.

iwegner/MITK,rfloca/MITK,lsanzdiaz/MITK-BiiG,nocnokneo/MITK,MITK/MITK,iwegner/MITK,RabadanLab/MITKats,lsanzdiaz/MITK-BiiG,MITK/MITK,iwegner/MITK,MITK/MITK,nocnokneo/MITK,danielknorr/MITK,iwegner/MITK,iwegner/MITK,fmilano/mitk,rfloca/MITK,lsanzdiaz/MITK-BiiG,nocnokneo/MITK,danielknorr/MITK,RabadanLab/MITKats,nocnokneo/MITK,rfloca/MITK,fmilano/mitk,nocnokneo/MITK,danielknorr/MITK,lsanzdiaz/MITK-BiiG,NifTK/MITK,nocnokneo/MITK,rfloca/MITK,RabadanLab/MITKats,RabadanLab/MITKats,NifTK/MITK,NifTK/MITK,NifTK/MITK,lsanzdiaz/MITK-BiiG,MITK/MITK,lsanzdiaz/MITK-BiiG,MITK/MITK,fmilano/mitk,danielknorr/MITK,rfloca/MITK,danielknorr/MITK,nocnokneo/MITK,danielknorr/MITK,lsanzdiaz/MITK-BiiG,NifTK/MITK,MITK/MITK,lsanzdiaz/MITK-BiiG,fmilano/mitk,rfloca/MITK,RabadanLab/MITKats,danielknorr/MITK,fmilano/mitk,rfloca/MITK,fmilano/mitk,RabadanLab/MITKats,NifTK/MITK,fmilano/mitk,iwegner/MITK