[REG 5.2.1 --> 5.3.2] qmlimportscanner invocation fails in static builds if sh.exe is in path

QtQuick Application fails with 'unable to scan qmlimportscanner output' if Qt is built staticaly and sh.exe is in the path variable.

Steps to reproduce:
1. Use static version of Qt 5.3.2
2. Add sh.exe to path
3. Create new QtQuick application
4. Invoke qmake

Actual result:
3. Command fails with 'unable to scan qmlimportscanner output'

The problem is the path for qmlimportscanner executable. It uses quotation marks that are not recognized by windows.
DEBUG 1: C:/qt/Qt5.3.2-ep-static/mkspecs/features/qt.prf:97: calling built-in $$system("\'C:\\qt\\Qt5.3.2-ep-static\\bin\\qmlimportscanner.exe\' C:/dev/eval/SimpleQuickStatic532 -importPath C:/qt/Qt5.3.2-ep-static/qml")

Same setup works with Qt 5.2.1.