QtVersion: Do not consider a valid Qt equal to an invalid Qt
QtVersion: Do not consider a valid Qt equal to an invalid Qt

Otherwise there is no changed signal once a Qt version becomes valid
which is required to e.g. re-check the validity of the kits that use
this Qt version.

Task-number: QTCREATORBUG-10222
Change-Id: I117fc08bd8ef775c50df654d760e4540e07e6c61
Reviewed-by: Daniel Teske <d8a411aec9a206efedb4d45b75fe8d13f1e2b628@digia.com>

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