WonderBrush Translator: fix warnings

src/add-ons/translators/wonderbrush/WonderBrushView.cpp: In constructor 'WonderBrushView::WonderBrushView(const BRect&, const char*, uint32, uint32, TranslatorSettings*)':
src/add-ons/translators/wonderbrush/WonderBrushView.cpp:58:8: warning: variable 'xbold' set but not used [-Wunused-but-set-variable]
src/add-ons/translators/wonderbrush/WonderBrushView.cpp:58:15: warning: variable 'ybold' set but not used [-Wunused-but-set-variable]
src/add-ons/translators/wonderbrush/WonderBrushView.cpp:64:8: warning: variable 'yplain' set but not used [-Wunused-but-set-variable]