ProjectExplorer: Fix build for Mac (Xcode < 5.1)
ProjectExplorer: Fix build for Mac (Xcode < 5.1)

Change-Id: I1ea1edbb0a5e15888cabadddbbb460d7c6f0b09b
Reviewed-by: Tobias Hunger <012f8d714267bccc9d4766fbeace9f175fcc70c4@digia.com>

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