fix issue where shipyard did not produce anything

src/lib/config/ConfigLoader.cpp

@@ -367,6 +367,8 @@ ShipsConfig ConfigLoader::loadShips(const std::string& path)
             def.blueprint.materials = parseIngredients(materials, file, bpPath + ".materials");
             def.blueprint.playerProductionLevel = static_cast<int>(requireInt(
                 bpMt["player_production_level"], file, bpPath + ".player_production_level"));
+            def.blueprint.productionTimeSeconds = requireDouble(
+                bpMt["production_time_seconds"], file, bpPath + ".production_time_seconds");
         }
 
         // Threat