svg_parser - fix bug introduced in previous commit.
svg_parser - fix bug introduced in previous commit.

tomhughes/mapnik,naturalatlas/mapnik,naturalatlas/mapnik,mapnik/mapnik,lightmare/mapnik,naturalatlas/mapnik,naturalatlas/mapnik,tomhughes/mapnik,mapnik/mapnik,lightmare/mapnik,mapnik/mapnik,tomhughes/mapnik,lightmare/mapnik,tomhughes/mapnik,lightmare/mapnik,mapnik/mapnik