Qt4ProjectManager: Remove unneeded #ifdefs.
Qt4ProjectManager: Remove unneeded #ifdefs.

Get host OS info at runtime.

Change-Id: I677fb093fefef7fbe341c972b828df5d81a04ef4
Reviewed-by: Friedemann Kleint <1b9f2592239daaec4856ccc1cfb4d2d55b35fb71@digia.com>

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