fix compiler warnings (GCC + Clang)

src/world/generator/GeneratorDef.cpp

@@ -8,7 +8,7 @@
 VoxelStructure::VoxelStructure(
     VoxelStructureMeta meta,
     std::unique_ptr<VoxelFragment> structure
-) : fragments({std::move(structure)}), meta(std::move(meta)) {}
+) : meta(std::move(meta)), fragments({std::move(structure)}) {}
 
 GeneratorDef::GeneratorDef(std::string name)
     : name(std::move(name)), caption(util::id_to_caption(name)) {