Wrong configure option to disable harfbuzz

Documentation in here says that -qt-harfbuzz can be used to avoid harfbuzz:
http://doc.qt.io/qt-5/qtgui-attribution-harfbuzz.html

Instead it probably should have said -no-harfbuzz since -qt-harfbuzz does compile the whole library and statically link to it. Perhaps this could be improved to say that -system-harfbuzz links dynamically, -qt-harfbuzz statically and -no-harfbuzz to avoid linking to harfbuzz.