Fix randomization issues

QtIdenticon.pro

src/identicon.cpp

src/identicon.h

src/identiconstyle.cpp

src/jdenticonplugin.cpp

src/jdenticonplugin.h

src/qtidenticon.cpp

src/rendering/colortheme.cpp

src/rendering/colorutils.cpp

src/rendering/icongenerator.cpp

src/rendering/icongenerator.h