debug: add a missing G_GNUC_PRINTF
debug: add a missing G_GNUC_PRINTF

gjtorikian/lasem,wavewave/lasem,gjtorikian/lasem,wavewave/lasem,gjtorikian/lasem,wavewave/lasem,janmarthedal/mathml2svg,janmarthedal/mathml2svg,gjtorikian/lasem,janmarthedal/mathml2svg,wavewave/lasem,janmarthedal/mathml2svg