fix assertion in CdbDebugEventCallback::UnloadModule
fix assertion in CdbDebugEventCallback::UnloadModule

Parameter ImageBaseName can be NULL.
This seems to happen for modules like kernel32.dll and other
modules in the guts of the OS.

kuba1/qtcreator,KDAB/KDAB-Creator,AltarBeastiful/qt-creator,KDAB/KDAB-Creator,duythanhphan/qt-creator,renatofilho/QtCreator,ostash/qt-creator-i18n-uk,darksylinc/qt-creator,pcacjr/qt-creator,darksylinc/qt-creator,bakaiadam/collaborative_qt_creator,pcacjr/qt-creator,richardmg/qtcreator,hdweiss/qt-creator-visualizer,danimo/qt-creator,sandsmark/qtcreator-minimap,amyvmiwei/qt-creator,jonnor/qt-creator,yinyunqiao/qtcreator,maui-packages/qt-creator,bakaiadam/collaborative_qt_creator,azat/qtcreator,azat/qtcreator,dmik/qt-creator-os2,AltarBeastiful/qt-creator,xianian/qt-creator,dmik/qt-creator-os2,ostash/qt-creator-i18n-uk,amyvmiwei/qt-creator,farseerri/git_code,yinyunqiao/qtcreator,dmik/qt-creator-os2,omniacreator/qtcreator,AltarBeastiful/qt-creator,omniacreator/qtcreator,duythanhphan/qt-creator,Distrotech/qtcreator,xianian/qt-creator,Distrotech/qtcreator,KDAB/KDAB-Creator,darksylinc/qt-creator,farseerri/git_code,richardmg/qtcreator,renatofilho/QtCreator,duythanhphan/qt-creator,KDE/android-qt-creator,maui-packages/qt-creator,AltarBeastiful/qt-creator,yinyunqiao/qtcreator,ostash/qt-creator-i18n-uk,KDAB/KDAB-Creator,azat/qtcreator,azat/qtcreator,farseerri/git_code,AltarBeastiful/qt-creator,richardmg/qtcreator,syntheticpp/qt-creator,colede/qtcreator,darksylinc/qt-creator,omniacreator/qtcreator,syntheticpp/qt-creator,kuba1/qtcreator,syntheticpp/qt-creator,martyone/sailfish-qtcreator,KDAB/KDAB-Creator,sandsmark/qtcreator-minimap,yinyunqiao/qtcreator,kuba1/qtcreator,bakaiadam/collaborative_qt_creator,darksylinc/qt-creator,renatofilho/QtCreator,KDE/android-qt-creator,malikcjm/qtcreator,AltarBeastiful/qt-creator,ostash/qt-creator-i18n-uk,pcacjr/qt-creator,dmik/qt-creator-os2,colede/qtcreator,hdweiss/qt-creator-visualizer,AltarBeastiful/qt-creator,colede/qtcreator,kuba1/qtcreator,sandsmark/qtcreator-minimap,hdweiss/qt-creator-visualizer,ostash/qt-creator-i18n-uk,colede/qtcreator,kuba1/qtcreator,danimo/qt-creator,syntheticpp/qt-creator,colede/qtcreator,bakaiadam/collaborative_qt_creator,richardmg/qtcreator,kuba1/qtcreator,maui-packages/qt-creator,amyvmiwei/qt-creator,danimo/qt-creator,xianian/qt-creator,malikcjm/qtcreator,bakaiadam/collaborative_qt_creator,dmik/qt-creator-os2,kuba1/qtcreator,duythanhphan/qt-creator,amyvmiwei/qt-creator,richardmg/qtcreator,KDE/android-qt-creator,Distrotech/qtcreator,maui-packages/qt-creator,pcacjr/qt-creator,xianian/qt-creator,KDE/android-qt-creator,xianian/qt-creator,dmik/qt-creator-os2,bakaiadam/collaborative_qt_creator,KDAB/KDAB-Creator,malikcjm/qtcreator,omniacreator/qtcreator,dmik/qt-creator-os2,maui-packages/qt-creator,martyone/sailfish-qtcreator,martyone/sailfish-qtcreator,farseerri/git_code,amyvmiwei/qt-creator,duythanhphan/qt-creator,danimo/qt-creator,ostash/qt-creator-i18n-uk,azat/qtcreator,kuba1/qtcreator,darksylinc/qt-creator,darksylinc/qt-creator,bakaiadam/collaborative_qt_creator,omniacreator/qtcreator,yinyunqiao/qtcreator,farseerri/git_code,yinyunqiao/qtcreator,syntheticpp/qt-creator,xianian/qt-creator,omniacreator/qtcreator,sandsmark/qtcreator-minimap,ostash/qt-creator-i18n-uk,Distrotech/qtcreator,martyone/sailfish-qtcreator,amyvmiwei/qt-creator,danimo/qt-creator,danimo/qt-creator,KDE/android-qt-creator,kuba1/qtcreator,duythanhphan/qt-creator,pcacjr/qt-creator,hdweiss/qt-creator-visualizer,xianian/qt-creator,richardmg/qtcreator,KDE/android-qt-creator,jonnor/qt-creator,colede/qtcreator,malikcjm/qtcreator,malikcjm/qtcreator,KDE/android-qt-creator,omniacreator/qtcreator,colede/qtcreator,syntheticpp/qt-creator,Distrotech/qtcreator,xianian/qt-creator,Distrotech/qtcreator,martyone/sailfish-qtcreator,duythanhphan/qt-creator,Distrotech/qtcreator,amyvmiwei/qt-creator,sandsmark/qtcreator-minimap,malikcjm/qtcreator,KDE/android-qt-creator,jonnor/qt-creator,danimo/qt-creator,martyone/sailfish-qtcreator,martyone/sailfish-qtcreator,danimo/qt-creator,richardmg/qtcreator,syntheticpp/qt-creator,sandsmark/qtcreator-minimap,jonnor/qt-creator,jonnor/qt-creator,AltarBeastiful/qt-creator,hdweiss/qt-creator-visualizer,azat/qtcreator,renatofilho/QtCreator,amyvmiwei/qt-creator,jonnor/qt-creator,darksylinc/qt-creator,farseerri/git_code,danimo/qt-creator,martyone/sailfish-qtcreator,xianian/qt-creator,martyone/sailfish-qtcreator,renatofilho/QtCreator,farseerri/git_code,maui-packages/qt-creator,pcacjr/qt-creator,malikcjm/qtcreator,renatofilho/QtCreator,yinyunqiao/qtcreator,hdweiss/qt-creator-visualizer,pcacjr/qt-creator,maui-packages/qt-creator,farseerri/git_code