QtTextRenderStrategy::argbToRgba(): Fix oob array access.
QtTextRenderStrategy::argbToRgba(): Fix oob array access.

Signed-off-by: Guillaume Charifi <a1ba02f8a3a5bd0c96a43bf003d3751c15face10@sfr.fr>

OpenChemistry/avogadrolibs,OpenChemistry/avogadrolibs,OpenChemistry/avogadrolibs,ghutchis/avogadrolibs,ghutchis/avogadrolibs,ghutchis/avogadrolibs,ghutchis/avogadrolibs,ghutchis/avogadrolibs,OpenChemistry/avogadrolibs,OpenChemistry/avogadrolibs