QtVersionManager: Simplify the code
QtVersionManager: Simplify the code

by removing legacy upgrade code that should no longer be used anyway.
Remove the count of versions while at it.

Change-Id: I014a8934581761d3219fe41dc7888903e7d6a85c
Reviewed-by: Daniel Teske <d8a411aec9a206efedb4d45b75fe8d13f1e2b628@nokia.com>

amyvmiwei/qt-creator,kuba1/qtcreator,AltarBeastiful/qt-creator,martyone/sailfish-qtcreator,richardmg/qtcreator,kuba1/qtcreator,farseerri/git_code,kuba1/qtcreator,danimo/qt-creator,xianian/qt-creator,farseerri/git_code,amyvmiwei/qt-creator,danimo/qt-creator,maui-packages/qt-creator,syntheticpp/qt-creator,malikcjm/qtcreator,malikcjm/qtcreator,colede/qtcreator,xianian/qt-creator,duythanhphan/qt-creator,kuba1/qtcreator,malikcjm/qtcreator,KDE/android-qt-creator,colede/qtcreator,farseerri/git_code,malikcjm/qtcreator,duythanhphan/qt-creator,danimo/qt-creator,KDE/android-qt-creator,darksylinc/qt-creator,kuba1/qtcreator,kuba1/qtcreator,darksylinc/qt-creator,Distrotech/qtcreator,farseerri/git_code,maui-packages/qt-creator,martyone/sailfish-qtcreator,xianian/qt-creator,xianian/qt-creator,richardmg/qtcreator,maui-packages/qt-creator,richardmg/qtcreator,syntheticpp/qt-creator,maui-packages/qt-creator,richardmg/qtcreator,AltarBeastiful/qt-creator,omniacreator/qtcreator,farseerri/git_code,syntheticpp/qt-creator,danimo/qt-creator,omniacreator/qtcreator,xianian/qt-creator,KDE/android-qt-creator,Distrotech/qtcreator,syntheticpp/qt-creator,syntheticpp/qt-creator,richardmg/qtcreator,danimo/qt-creator,colede/qtcreator,amyvmiwei/qt-creator,Distrotech/qtcreator,darksylinc/qt-creator,AltarBeastiful/qt-creator,omniacreator/qtcreator,duythanhphan/qt-creator,omniacreator/qtcreator,martyone/sailfish-qtcreator,KDE/android-qt-creator,maui-packages/qt-creator,darksylinc/qt-creator,martyone/sailfish-qtcreator,maui-packages/qt-creator,colede/qtcreator,AltarBeastiful/qt-creator,martyone/sailfish-qtcreator,martyone/sailfish-qtcreator,colede/qtcreator,xianian/qt-creator,amyvmiwei/qt-creator,martyone/sailfish-qtcreator,AltarBeastiful/qt-creator,farseerri/git_code,richardmg/qtcreator,duythanhphan/qt-creator,omniacreator/qtcreator,KDE/android-qt-creator,xianian/qt-creator,malikcjm/qtcreator,martyone/sailfish-qtcreator,farseerri/git_code,colede/qtcreator,kuba1/qtcreator,darksylinc/qt-creator,kuba1/qtcreator,amyvmiwei/qt-creator,duythanhphan/qt-creator,AltarBeastiful/qt-creator,kuba1/qtcreator,duythanhphan/qt-creator,maui-packages/qt-creator,darksylinc/qt-creator,amyvmiwei/qt-creator,darksylinc/qt-creator,syntheticpp/qt-creator,richardmg/qtcreator,Distrotech/qtcreator,danimo/qt-creator,malikcjm/qtcreator,malikcjm/qtcreator,KDE/android-qt-creator,amyvmiwei/qt-creator,syntheticpp/qt-creator,KDE/android-qt-creator,xianian/qt-creator,AltarBeastiful/qt-creator,Distrotech/qtcreator,omniacreator/qtcreator,colede/qtcreator,farseerri/git_code,danimo/qt-creator,KDE/android-qt-creator,darksylinc/qt-creator,amyvmiwei/qt-creator,duythanhphan/qt-creator,Distrotech/qtcreator,danimo/qt-creator,Distrotech/qtcreator,martyone/sailfish-qtcreator,omniacreator/qtcreator,danimo/qt-creator,AltarBeastiful/qt-creator,xianian/qt-creator