$CXXFLAGS and $LDFLAGS undefined?

[ybycode]

Hi,

Aren't the $CXXFLAGS and $LDFLAGS undefined in the build image Dockerfile?

docker-alpine-wkhtmltopdf/src/Dockerfile

Lines 53 to 55 in 84c78cd

	&& sed -i "s|-O2|$CXXFLAGS|" mkspecs/common/g++.conf \
	&& sed -i "/^QMAKE_RPATH/s| -Wl,-rpath,||g" mkspecs/common/g++.conf \
	&& sed -i "/^QMAKE_LFLAGS\s/s|+=|+= $LDFLAGS|g" mkspecs/common/g++.conf