remove unused include (#include <mapnik/json/value_converters.hpp>)
remove unused include (#include <mapnik/json/value_converters.hpp>)

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